I got some feedback.
I played harbinger 26 dirgesinger 4, Crimson count, to lvl 30, and then further.
Lets go chronologically.
Dark Claim: No where it says it resets on a kill the way old hex used to, but it does, and whether or not it's a bug or a feature remains mystery. In case it's a feature, it's a bit wonky as mobs with corpses who wont despawn will occupy the dark claim until the full cd is over because it only resets if the corpse despawns. In case it's a bug - oops.
Atrocity strike: A lot like dark harvest, and especially for crimson count, you need to use the strike to execute, and while it's nice and interesting and also has bonus damage * missing health%, it's still incredibly hard to use optimally and extremely punishing to mistime it. It is not the fun part of the class, for sure.
Atrocity whisper and invocations: completely garbage. Not ever worth using. They behave like a potion use, in that they proc attack of opportunity, and they also behave similarly to a wand in how they fire-off when you use them (meaning you need to finish your round before it fires and then your next action is only 3 seconds later and I dont think haste affects this as far as I can tell).
The crimson count on-kill bonus: Questionably good. The heal is not that hot but the DR is absolutely fantastic (in endgame dungeons you get the 11/+6 very often) and I question whether or not it's fine that it doesnt have any scaling with harbinger lvl, and even a 8 harbi 7 wm 16 cot, for example, can utilize it to about the same value. It's currently the most fun part of the kit, for me, if we ignore the annoying execute mechanic it relays on. I also slapped Mortality Undone and some DI% gear where I could so it really felt like a good middle ground between high ac and decent drain-tanking over all.
I am not going to comment on other paths much because I feel like they facilitate completely different things (like a DC focused pure harbi with acedia, woe drinker, 18+ cha and the path with the bonus DCs on curses etc) which I havent tested or played live yet. But I see the potential, at least in theory. It sounds like it can get really mean DCs, especially in this twilight zone meta between dwaemo systems. I'd keep an eye on those builds.
My two cents on the power creep:
I have not pvped on this class yet, but I can say from playing similar classes and character architypes, that the wind up is definitely not the shortest, and even more so if you dip dirge singer to boost your effective stats even more through lvl 20+ curse song, but the stats are definitely on the stronger side of things. It gets really juicy stats when it gets the haste, div might+shield, curse song going. I did not have a real issue with skills because I didnt try to squeeze stealth into it, and I think I like it that way. stealth max would be no brainer if the skill points were more loose than this so I can see the logic here.
Over all, I like this class a lot. It was a lot of fun to level solo and it's capable of easily grinding the 2-3 easier runics we have, without relaying much on consumables, so its very self sufficient, which is definitely right up my ally. Big kudos to Amnesy and and anyone else involved.