Affliction:
Soul Siphon rune redesigned: Combines Drain life and Drain mana into a single 15, 18 or 30 second dot named Soul Siphon that ticks every 3 seconds for the amount of 3x of the original spells ticks. Effectively being the same as casting of either spell for 15, 18 or 30 seconds. Can crit with pandemic except mana part. Mana drain portion can be adjusted for PVP. If Siphon life is learned. Increases the Drain life portion by the Siphon life amount effectively removing the need for one extra dot. This makes it easily counterable in pvp, just dispel if not protected by UA. Soul Siphon can procc nightfall.
Mark of Chaos redesigned: Dark Pact now scales 100% with spell power. In addition every time you cast Dark Pact, You and your pet get Mark of Chaos. Increasing pet damage by 5%, stacks 5 times. For you reducing Dot duration by 6% stacks 5 times. This would be interesting mechanic for example with new Felguard frenzy and ramping up dot damage.
I think decimation is good and suits destro playstyle well.
Improved Shadowbolt. Remove the stacks and just make it time based.
Soul well new skill book needed.
With redesigned Mark of Chaos, Invocation rune would yield one extra tick for the damage portion, effectively making dot playstyle very skill based.
Make Immolation aura 5% change to proc short immolate on target that can be consumed by conflagrate. Someone else suggested this on forums, dont remember who.
Waiting for new lake of fire to give feedback.
TY for reading.