Im really glad you liked it! I too use calamity and I too have hatred issues sometimes. I lowered my attack speed some and changed to evasive fire/covering fire and for now its really working out. It generates 4 hatred per shot, which is a little faster than bolas 3. Plus it backflips me 15 yards giving me the steady aim bonus instantly. Paired with caltrops and FA's slow I havent had much of a problem maintaining steady aim. I kill pretty fast though, critting whites up to 600k so maybe you just need to get your damage up a bit. It is indeed very fun actually being mobile, running around and dropping big crits :D
edit: scoundrel with windforce or buriza helps a ton. I really like WF as it pushes them out of range and helps with steady aim
if your only using frostburns (based on your gear, I could be totally wrong) then you wont get the maximum out of this build. You really need an EA DML and SoJ at least alongside them. I kept testing this and RF kept winning out until I hit a certain +%Elemental Arrow, then FA hit a breaking point where I was getting more damage out of it than RF.
I solo MP8-10 with this gear btw
I like Bola Shot-Bitter Pill for the disc regeneration, and as much as I love Evasive Fire-Covering Fire the backflip can actually get you in to trouble depending on where you are farming. If you port in from a waypoint and haven't cleared the map yet, you might find yourself back flipping in to more monsters, and if you keep spamming evasive fire, it will probably happen a few times before you realize what happened. Hardened is an option, but one shot for 130% weapon damage is pretty weak.
I'm still playing around trying to get a feel for what skills/rune combos I think are best for the build.
Shadow Power-Gloom : Absolutely must have, even with playing a distance build there are times when you need the damage reduction, and more importantly the life steal.
Elemental Arrow-Frost Arrow : Obviously the focal point of the build.
Companion- Bat : Must have for the hatred regeneration.
--- After this it becomes less clear what is the best options for skills. ---
Hungering arrow is a good single target DPS generator with the Devouring Arrow rune, but honestly when you start talking monster power there are so few times single-target is a good idea. Even with the piercing effect, if you are out of hatred and need to do some damage for the SP lifesteal proc, this is not a good choice. Spray of Teeth is decent AoE damage, but not good enough to beat out Bola Shot.
Entangling shot with Justice is Served is the single best hatred generating option we have along with Grenades with Tinkerer. Despite the fact the damage is insanely low, the fact you can fire off a few shots and go back to spamming Frost Arrow really makes up for it. It would be tough to use under pressure situations where you need lifesteal, but I think overall this is a very strong option for a hatred generator.
Bola Shot is great with Bitter Pill or Imminent Doom depending on your discipline usage. I've personally been using this as my hatred generator with every end-game build. The AoE DPS is great and extra discipline is awesome as well. This is also another strong choice. If you can fit Preparation in your build, relying on Bitter Pill is not as necessary.
Grenades with Tinkerer provides another strong option for hatred generation, but honestly Entangling shot has more synergy with the build since the snare works with Cull the Weak. It does slightly more damage, but I don't think that makes up for it. I would go with Entangling Shot instead every time.
Evasive Fire is a more interesting choice. the added element of a back flip works well in conjunction with steady aim and it sits right in the middle as far as hatred regeneration is concerned, at 4 per. Hardened is a good rune option since it eliminates the risk of back flipping in to more monsters and removes any discipline costs.
Caltrops, Preparation, Rain of Vengeance, Vault and Smoke Screen all make great cases to be supplemental skills in this build. If you use evasive fire with the back flip, you do not need Vault. Smoke Screen is very situational and in most cases you should be avoiding being in a position to need an "oh crap!" button. Caltrops has great synergy and the extra 10% CC from Bait the Trap is awesome. Preparation is like Bola Shot - Bitter Pill in that you only need it if you are using a lot of discipline which I find myself doing on elite packs to keep up the life-steal. Rain of Vengeance with Beastly Bombs packs a ton of punch and makes for a great, no-cost AoE every 30 seconds. If only it was cold damage.
Cull the Weak : Self-explanatory, must have.
Archery : Every build should have Archery, except for gimmick builds not using a bow of some sort; end of story.
--- The last slot is open for interpretation. ---
Steady Aim is situational, but great if you are good at keeping the distance, the problem is if even one enemy sneaks up on you, you lose the bonus. I really hate that. Especially for fast moving mobs that go all over the place like ghosts, burrowers, imps, and plaguewings.
Perfectionist is a great defense first option. It also helps with your discipline management.
Nightstalker/Vengeance are both good resource generators if you are lacking there.
I guess Grenadier is an option if you really want that extra 2 hatred per using Grenades, but it seems like a wasted passive to me. The last two bonuses on it need serious reworking.
All in all this is a very open build with different options depending on gear and play style.