Sorry for the wall of text 
At the link below you can find an explanatory image of the new modified tree.
Regardless of the changes I’ve made to the talents, I feel like the tree structure I’m proposing is more coherent, in the placement of talents and how to get them, and more flexible than the current one, allowing us to take whatever we want without running into talents we don’t like.
Link → https: //ibb. co/D7swJZP
EARTH SHOCK (Reworked Talent)
Consume 60 Maelstrom / Instant
Instantly shock the target with concussive force, causing (400% of Spell power) Physical damage and has a 20% change to knock the enemy down.
EARTHQUAKE (Talent)
Consume 60 Maelstrom / Instant
Causes the earth whithin 8 yards of your target (or target location) to tremble and break, dealing [Spell power * 0,5 * 6 / 1 * (1 + Versatility) *1 *1 *1 *1 *1] Physical damage over 6 sec and has a 5% chance t knock the enemy down. Multiple uses of Earthquake may overlap.
I think our spenders should be neutral. Earth Shock (like Earthquake) now deals physical damage. I also added the knock down effect to make it consistent with Earthquake. A little plus for PVP.
ELEMENTAL FURY (Talent)
Your damaging critical strikes deal 250% damage instead of the usual 200%.
SURGE OF POWER (Reworked Talent)
Earth Shock, Elemental Blast and Earthquake enhance your next spell cast within 15 sec:
- Flame Shock: The next cast also applies Flame Shock to 1 additional target within 8 yards of the target.
- Lightning Bolt: Your next cast will cause 2 additional Elemental Overloads.
- Chain Lightning [or Lava Beam]: Your next cast will chain to 1 additional target.
- Lava Burst: Reduces the cooldown of your Fire and Storm Elemental by 6,0 sec.
- Frost Shock: Freezes the target in place for 6 sec.
I put in Lava Beam and changed the LvB effect back to 6 sec because with the current changes to our elementals, with five LvB I can align my elemental with ascendance.
MASTER OF THE ELEMENTS (Reworked Talent)
Casting Lava Burst [or Lava Beam] increases the damage or healing of your next Nature spell by 15%.
Casting Lightning Bolt or Chain Lightning increases the damage of your next Frost spell by 15%.
Casting Frost Shock or Icefury increases the damage of your next Fire spell by 15%.
I added the Flux Melting effect because it’s a useless talent, on its own, as icefury doesn’t activate often enough to make it necessary.
ICEFURY (Reworked Talent)
Generates 12 Maelstrom / Instant
Lightning Bolt, Chain Lightning [or Lava Beam]and Lava Burst has a 10% change to replace your next Frost Shock with Icefury. Hurls frigid ice at the target, dealing (430% of Spell power) Frost damage and causing your next 2 Frost Shocks to deal 150% increased damage, damage 4 additional target and generate 7 additional Maelstrom.
It’s more useful to have two Frost Shocks than to be able to stack two Icefury.
FUSION OF ELEMENTS (Reworked Talent)
After casting Icefury, the next time you cast a Nature and a Fire spell, you additionally cast an Elemental Blast at your target at 20% effectiveness.
Fusion has been nerfed because, as you’ll see later, Elemental Blast should become a very powerful hit, similar to Chaos Bolt.
ELEMENTAL EQUILIBRIUM (Talent)
Dealing direct Fire, Frost and Nature damage within 10 sec will increase all damage dealt by 10% for 10 sec. This can only occur once every 30 sec.
IMPROVED FLAMETONGUE WEAPON (Talent)
Imbuing your weapon with Flametongue increases your Fire spell damage by 5% for 1 hour.
ELECTRIFIED WEAPON (New Talent)
Instant
Imbue your weapon with Electrified Weapon increases your Nature spell damage by 8% for 1 hour.
I think it’s better to make the school upgrade (Nature/Fire) a choice and have both on the weapon. Forcing us to use the shield is very inconvenient.
UNDERELENTING CALAMITY (Talent)
Reduces the cast time of Lightning Bolt and Chain Lightning by 0,25 sec.
Increases the duration of Earthquake by 1 sec.
STORM FRENZY (Reworked Talent)
Your next Lighting Bolt or Chian Lightning has 50% reduced cast time after casting Earth Shock, Elemental Blast or Earthquake. Can you accumulate up to 2 charges.
The effect needs to be buffed and not nerfed, otherwise it becomes a useless talent.
THUNDERSTRIKE WARD (Reworked Talent)
While Lightning Shield is active, Lightning Bolt and Chain Lightnning have 20% change to call down 2 Thunderstrikes on your target for (70% of Spell power) Nature damage.
Now applies to Lightning Shield. I find this more consistent, since Lightning Shield already has an effect that hits enemies.
FLASH OF LIGHTNING (Reworked Talent)
Increases the critical strike change of Lightning Bolt, Chain Lightning, Thunderstrike Ward and Storms Overlord by 10%.
Now interacts with all of our lightning damage sources.
STORMKEEPER (Reworked Talent)
1,0 min cooldown / 1,5 sec cast
Charge yourself with lightning, causing your next 2 Lightning Bolts to deal 150% more damage, and also causes your next 2 Lightning Bolts or Chain Lightning to be instant cast and trigger al Elemental Overload on every target.
LIGHTNING ROD (Reworked Talent)
Earth Shock, Elemental Blast and Earthquake make your target a Lightning Rod for 12 sec. Lightning Rods take 30% of all damage you deal with Lightning Bolt, Chain Lightning, Thunderstrike Ward and Storms Overlord.
I merged LR with the proposed talent (Charged Conduit). With two separate talents, it feels like we’re back to when we had to spend 0/2 points for a full talent.
STORMS OVERLORD (New Talent)
2,0 min cooldown / Channeled 3 sec cast
Dealing, up to 5 enemies near the target, [3*(250% of Spell power)] Nature damage evenly split to each enemy target over 3 sec. At the end of the channeling Generate 4 Maelstrom for tick. (Total 3x4=12 Maelstrom)
I was inspired by Fae Transfusion. It would help Stormbringer builds in ST which is currently weak. The animation could be lightning bolts hitting targets from above while channeling.
POWER OF THE MAELSTROM (Talent)
Casting Lava Burst has a 60% change to cause your next Lightning Bolt or Chain Lightning cast to trigger Elemental Overload an additional time, staking up to times.
ELECTRIC BURST (New Talent)
Your instant Lava Burst make your target a Lightning Rod.
This talent tries to answer the question: why do I need to use Flame Shock and Lava Burst in Stormbringer builds? We can’t ask to replace or remove these two spells. Now it is necessary to always keep Flame Shock active and the Lava Surge procs will help us spread Lightning Rod.
FLOW OF POWER (New Talent)
Increases the Maelstrom generated by Lightning Bolt and Lava Burst by 2.
ECHO CHAMBER (Talent)
Increases the damage dealt by your Elemental Overloads by 40%.
MOUNTAINS WILL FALL (Reworked Talent)
Eart Shock, Elemental Blast and Earthquake can trigger your Mastery: Elemmental Overload at 60% effectiveness.
Overloaded Earth Shock and Earthquake do not knock enemied down.
STORM ELEMMENTAL (Reworked Talent)
2,5 min cooldown / Instant
Calls forth a Greater Storm Elemental to hurl gusts of wind that damage the Shaman’s enemies for 30 sec.
While the Storm Elemental is active, casting Lighting Bolt or Chain Lightning increases your haste by 4%, staking up to 4 times.
The basic attack jump on a 2 nearby enemies. (Affects 3 total target)
The basic attack (with Primal Elementalist) jump on a 4 nearby enemies. (Affects 5 total target)
FIRE ELEMENTAL (Reworked Talent)
2,5 min cooldown / Instant
Calls forth a Greater Fire Elemental to rain destruction on your enemies for 30 sec.
While the Fire Elemental is active, Flame Shock deals damage 30% faster, and newly applied Flame Shocks last 100% longer.
The basic attack hit 1 target.
The basic attack (with Primal Elementalist) hit 1 target and will always critical strike if the target is affected by Flame Shock.
SWELLING MAELSTROM (Reworked Talent)
Increases your maximum Maelstrom by 50.
Generates 1 Maelstrom every 2 sec.
When you are not in combat the maximum Maelstrom generated is 10.
The change to Swelling Maelstrom helps us with Maelstrom generation, which is a big problem, and having some Maelstrom (max 10) between pulls.
ECHO OF THE ELEMENTS (Reworked Talent)
Lava Burst and Flame Shock has an additional charge.
Having two stacks of Flame Shock (coupled with Path of Flame) helps us spread and keep Flame Shocks active.
VULCANIC INFERNO (New Talent)
Lava Burst have 20% change to open a volcanic fissure under your target, dealing [6*(15% of Spell power)] Fire Damage over 6 sec to all enemies within 3 yards of the target.
This is a controversial talent in Legion, but I find it very themed with Elemental. If getting decent hits on enemies is a big problem, it can be improved in two ways: increasing the range or making it instant.
LAVA BEAM (New Talent)
1,5 sec cast / generates 2 Maelstrom for target hit
Lava Beam replace Chain Lightning.
Unleashes a blast of superheated flame at the enemy, dealing (90% of Spell power) Fire damage and then jumping to additional nearby enemies. Damage is increased by 10% after each jump. Affects 3 total targets.
Many have asked to replace Chain Lightning with Lava Beam. Now it is an optional talent so it is not mandatory to take it but whoever wants it can use it.
PRIMORDIAL WAVE (Reworked Talent)
30 sec cooldown / Instant
Blast your target with a Primordial Wave, dealing (65% of Spell power) Elemental damage and applying Flame Shock to them.
Your next Lava Burst will also hit all targets affected by your Flamme Shock for 60% of normal damage.
I brought the damage up to 65% to make it effective.
SPLINTERED ELEMENTS (Talent)
Primordial Wave grants you 10% haste plus 4% for each additional Lava Burst generated by Primordial Wave for 12 sec.
FLAMES OF THE CAULDRON (Talent)
Reduces the cooldown of Flame Shock by 1,5 sec and Flame Shock deal damage 15% faster.
SEARING FLAMES (Reworked Talent)
Flame Shock damage has a 25% change to generate 2 Maelstrom and Flame Shock has a 50% increased critical strike change.
With the loss of Skybreaker’s Fiery demise, Flame Shock’s damage has been significantly reduced. Searing Flames is an underused talent, but with this change it will definitely be picked up in Fire AOE builds.
MAGMA CHAMBER (Talent)
Flame Shock damage increases the damage of your Earth Shock, Elemental Blast or Earthquake by 1,5%, stacking up to 10 times.
ERUPTING LAVA (Reworked Talent)
Increases the duration of Flame Shock by 6 sec and the damage by 20%.
Lava Burst overloads benefit at 50% effectiveness.
I removed the part that reduces the duration of Flame Shock because it makes it an unplayable talent (PvP and PvE). I left the rest and I think it’s nice that Elemental Overloads hit for 50% damage instead of 25% (Mastery).
PATH OF FLAME (New Talent)
Lava Burst deals 10% more damage and causes Flame Shock to spread from the target to a 4 yards nearby enemy.
This talent is better than Liquid Magma Totem because it is useful in AOE but also in ST. Also, with the double charge of Flame Shock from EotE, LMT is no longer needed and I will have one less GCD.
ELEMENTAL RAGE (Reworked Talent)
Your damaging spell incite the elements around you to come to your aid for 6 sec, repearedly dealing (30% of Spell power) Elemental damage to your most recently attacked target. While you have an elemental active, increases the activation rate of Elemental Rage.
With this change, it benefits from both Nature and Fire buffs. Visually, there would be: a lava-covered shard, an ice-covered shard, and an electrified shard.
ELEMENTAL UNITY (Talent)
While a Storm Elemental is active, your Nature damage dealt is increased by 10%.
While a Fire Elemental is active, your Fire damage dealt is increased by 10%.
EVERLASTING ELEMENTS (Talent)
Increases the duration of your Elementals by 20%.
ECHO OF THE ELEMENTS (Talent)
When your Storm Elemental or Fire Elemental expires, it leaves behind a lesser Elemental to continue attacking your enemies for 10 sec.
PRIMAL ELEMENTALIST (Reworked Talent)
Your Earth, Fire and Storm Elementals are drawn form primal elementals 100% more powerful than regular elementals, with additional abilities, and you gain direct control over them.
Our elemental buffs have been placed all close together. The placement of Elemental Unity makes no sense. With the changes to elementals (see above) and Primal Elementalist, you should be able to feel the difference between normal and enhanced elementals.
AFTERSHOCK (Reworked Talent)
Earth Shock, Elemental Blast and Earthquake have 25% change to summon four Little Elementals that increase your combat capabilities for 8 sec.
Fire - increases the chance to trigger Elemental Overload by 10%
Storm - generates 2 maelstrom every 1 sec
Ice - increases your critical strike damage by 10%
Earth - granting the caster a shield absorbing (400% of Spell power) for 15 sec and up to an additional (400% of Spell power) every 4 sec.
I was inspired by Totem Mastery but with the intention of not having static totems. Elementals seem like the best option because they can follow us and are Elemental themed. They grant small buffs and a small shield.
EYE OF THE STORM (Talent)
Reduces the Maelstrom cost of Earth Shock and Earthquake by 5.
Reduces the Maeltrom cost of Elemental Blast by 10.
ECHOES OF GREAT SUNDERING (Reworked Talent)
After casting Earth Shock, your next Earthquake deals 130% additional damage.
ELEMENTAL BLAST (Reworked Talent)
Consume 80 Maelstrom / 2,5 sec cast
Harnesses the raw power of the elements, dealing (600% of Spell power) Elemental damage and increasing your Critical Strike or Haste by 3% or Mastery by 6% for 10 sec.
Elemental Blast has changed its stats and becomes a powerful damage option, inspired by Chaos Bolt.
ASCENDANCE (Talent)
3,0 min cooldown
Transform into a Fire Ascendant for 15 sec, instantly casting Flame Shock and a 100% effectivess Lava Burst at up to 6 nearby enemies. While ascendend, Elemental Overload damage is increased by 150% and spells affected by your Mastery: Elemental Overload cause 1 additional Elemental Overload.
FIRST ASCENDANT (Talent)
The cooldown of Ascendance is reduced by 60 sec.
PREEMINENCE (Talent)
Your haste is increased by 25% while Ascendance is active and its duration is increased by 3 sec.
DEEPLY ROOTED ELEMETS (Reworked Talent)
Casting EarthShock, Elemental Blast or Eathquake have 15% change to activate Ascendance for 6 sec.
Now that it activates with our big spenders, it needs to have an activation boost or a longer duration.
STORMBRINGER
Tempest should work like this: Every 300 Maelstrom spent , the next time you cast Lighting Bolt or Chain Lightning, you additionally cast Tempest at your target. Nerf Tempest if needed.
Replace Rolling Thunder with Fury of the Storm.
FARSEER
For me Farseer should use all elements (Fire/Lightning/Ice) or at least a combination of the two (Fire/Ice) or (Fire/Lightning) with a little more emphasis on fire.