I've started my first hc char as DH and am at lvl 42 now, almost at end of act 2 nightmare.
Probably obvious stuff but here goes:
- i prioritise vit above dex, but look for cheap vit/dex gear on AH
- every 5-ish levels, i upgrade my 1h xbow weapon via AH to the highest DPS/dex i can find
skillwise my main ones are splitting arrow (the one that breaks into 3 more), frost arrow, vault and caltrops 80%
So far so good and not too much trouble. Only problem i had so far was in a dungeon vs arcane waller. was completely stuck in wall with no way out and 2 arcane bubbles spawning near me. got out with 10% hp through some frantic button bashing / panicing.
i m also looking for some tips to handle the next diff levels, as this is my first DH.
As you approach the higher difficulties, I'd strongly suggest picking up a quiver and chest (possibly a 1h xbow as well) with +max discipline. Having that extra smoke screen available (2 with preparation) can be a real life server when you need to escape. +Move speed is also a very underrated stat, that can greatly increase your chances of surviving when you need to make a run for the door versus a pesky group of spiders or other fast mobs. Helps a lot in general kiting as well, making it a good stat both offensive and defensive.
Other than that, prioritize vitality and other survivability stats on your gear. Just get a pretty high dps weapon to go with and you'll be fine up untill at least Hell act 1 (which is where I'm at now) as long as you're not reckless.
Skill tips: IMO, there are three must-haves for skills
1. Smoke Screen (preferrably with extended duration rune)
2. Caltrops. DH is all about kiting. I like the 2sec snare rune until NM, then its the 80% slow rune for me
3. Preparation. You will almost never use this at lower lvls if you play like I do (NEVER use your getaway skills for fast lazy travel, so you have them available when you need it) but you WILL eventually use it, and it WILL give you that extra discipline to save your ass. Also, once you unlock the heal rune for it, it is absolutely essential.
Some other nice skills are Bola shot with the added aoe rune, and rapid fire with the low cost rune. I think that is the attack skill setup I used most while lvling. elemental arrow with the slow moving lightning ball is also fairly nice.
Beware, the scariest areas for me as a DH have been a4..... The first two bosses (of a4) were scary as hell in NM, Iskatu and the Rakanoth. When it comes to any boss fights in nm and on, I always go to normal mode and practice escape and evasion tactics on bosses before actually attempting them in nm/hell. This has been HUGE for survivability.
Hope this info helps up-and-coming HC DH's
And, of course, this is all just my opinion based on what I have experienced so far.
EDIT: I forgot to mention I used a 2her with a quiver until NM, then switched to a 1her with a shield.