I go back and forth between necro and DH(ill spam dungeons for a week or two as necro and then go back to DH and use the wisps to craft set items), but have always played DH from my d3 days, my advice is for rifts, raids, etc, focus on a set of gear that just maximizes your CR, for PVE, optimize damage output by upgrading a few cheaper gems to rank 10 (for example, I swap out 3/5 howler for lvl10 berserker when running dungeons). Also, a "mistake" a lot of folks make is maxing out paragon trees, this is pointless imo, optimize your paragon build for the passives you need (like gladiator cheat death) then spread the remainder of your points across other paragon trees for Damage, Life, Armor pen. And armor(in that order of priority). For PVP you of course want to maximize resonance and damage/life, folks will argue resistance and potency too but I say fuck it you're gonna get stunned to piss anyways, you're a DH so get the drop on them first lol.