You’ll want to sim stuff once 8.3 stuff can be simmed. You can then start setting your goals.
Stat priorities can be found in the icy veins guide. Versatility above all, mastery and agility are the worst. These might change in 8.3 and might change based on your gear, so you will always have to sim your upgrades.
This is what I currently recommend for 8.2. Trait wise I don’t know if much changes in 8.3, though I do know Overwhelming Power will get nerfed for DH so it might sim a bit lower and open alternatives. Comparing my spellbar to that of my Demon Hunter - #133 by Linaori-chamber-of-aspects
Essences in 8.3 will receive an overhaul, such as life-force will be nerfed and new essences will be introduced, thus my essences will probably be sub-par for 8.3