Thank you Nyan very much for the detailed breakdown!

That was quite a bit to digest; but I think I picked up quite a few things which seemed to stand out to me a particularly important/flagged for implementation (later tonight)

-Sustain: I think the bat familiar gives a good hatred regen? is this what you mean by sustain? I also have a fair amount of LoH (although more could always be better, and I can look into some LS gear) which synergies well with rapidfire for sustaining health
-Mobility: This was actually my favorite thing about DH and the thing that stood out to me when I started playing the class. Vault/Tumble hasn't left my skillbar since I got it. I can get in and out of trouble pretty easily with that; not to mention I can run through certain areas like entire spans of silver spire to the next teleporter beacon which is handy in group games when people just wanna get through without fighting everything
-Resource Management: My big hatred spender is rapidfire; I have the bat to boost that, I have tried to stay away from IAS stuff to keep the channeling cost down; I don't find myself running out of rapidfire often, but I can vault away and shoot a bolo or two and be ready to rapidfire for a fair bit again
-Damage Dealer; Rapidfire/High Velocity; good single target/AoE due to penetration
-Attack Speed: Still kinda confused about this one; I think I'm trying to keep mine low to maximize rapid-fire time; is that ok?
-Crit Chance: Don't know off the top of my head, but I think my CC is 50+ and my CD is 250+; I guess this is a start; should I continue to improve those two approximately proportionately? or is one in need of more work than the other?
-Discipline: I don't seem to use this for much other than mobility and shadow power; and don't find myself running out too often unless I do something silly like vault around too much and find myself in the middle of a ton of enemies without discipline to shadowpower; but that's not really a build issue, that's more a something dumb I can choose not to do
-Hatred Regen: I got the bat, and I think one of my items gives some boost to that; are there any particular gears that help this? or skills I can use in conjunction with the bat? (Other than the shadow power hatred regen; since I understand now that Gloom is much more important)

The other thing I think I should try; If I'm understanding this correctly is;

swap my turret for spike trap; I'm game to do this; I don't really use that turrent that often; In fact I mainly seem to be using vault/shadow power/rapidfire; everything else is support or utility or novelty on top of that. I am very willing to experiment with different alternative skills.

and try get a calamity to experiment with; calamity is a 1h crossbow right? So I take it I want a socketed one I can put an emerald in for some more CD; do I dual wield with that? or am I using that with a quiver for a higher attack speed build? will that negatively affect my ability to use rapidfire?

I get that this is a pretty huge post! Just kind of a stream-of-counciousness; I'm going to try incorporate spike-trap over turret into the build and do some re-gearing later tonight. If you could give this a read through at your convenience and tell me if I understood anything completely incorrectly or answer a few questions; that would be greatly appreciated.

Thanks for the detailed explanation for DH class nonetheless!