Stance Restrictions
I think that stance restrictions should be removed from DRK. The Grit MP reduction to 1200 MP this patch suggests that the devs are fairly cautious about allowing us freedom to change stances. This is fine, but this should also be reflected in our job design. Leave the conditional stance abilities for jobs that have the freedom to change stances on oGCD, with no attached resource cost.

Take PLD, for example. Changing stance is costly. As a result, there are no stance restricted abilities or effects. You don't lose access to passive blocking when you're not in Shield Oath. You don't lose access to Fight or Flight outside of Sword Oath. This is very sensible. It should be applied to DRK's design.

Souleater should heal outside of Grit. It doesn't matter if it's a smaller heal, or if it only occurs as a Dark Arts effect, but it should be there. If you can have healing on Storm's Path irrespective of stance, you can certainly find a way to have it on Souleater.

I understand the caution around Blood Price's resource generation. At this point, though, I'd rather see the ability removed and applied as a trait on Shadow Wall. The longer recast on the effect would allow it to be tuned to have more single target value, and it'd add a bit of personality to Shadow Wall.

Blood Weapon is another ability that shouldn't be really be stance-dependent. You can use FoF, Req, and IR in whatever stance you like.

Burst
I do think that DRK suffers as far as burst is concerned. Most burst windows increase your output over fewer GCDs. This is what you want. It means that you get more powered-up hits out under raid buffs. It also gives you an edge in lower uptime fights, because your buffs are up for a higher proportion of the 'active' fight.

DRK's approach to burst is to push out damage for longer. Blood Weapon allows you to support more DA usage, but doesn't make DA stronger. Delirium extends Blood Weapon without adding any extra impact to each hit.

While the thought of making Blood Weapon faster sounds appealing, I think you'll run into a problem with clipping. The new Plunge animation lock is nice, for example, but there's probably an upper bound on how fast you can make it. If people are running into clipping issues at a 10% speed boost, it's only going to get worse at higher speeds.

I think if you wanted to make DRK thematically faster than it is, you'd need something along the lines of a Duality type effect, where your Dark Arts empowered effect hits for a second time.

I think Blood Weapon itself is fine, but the bigger weakness is Delirium. The issue is a relatively underwhelming effect and a high cost. What I'd like to see is something along the lines of this:

Blood Weapon: Increase recast to 60s, increase duration to 20s.

Delirium: Replaces Blood Weapon at Lv. 62. Whenever Dark Arts is used under the effect of Delirium, the Dark Arts effect is applied for a second time (à la Duality).

We need to push out potency in a shorter span of time, rather than spreading it out.

Other issues
I think Sole Survivor is fantastic as it is. The resource gain is nice, but the really interesting part is the timed heal. I do think that having it cleanse Walking Dead would be a nice addition. At the very least, I do want to see some sort of a UI change to Living Dead that shows the amount of healing still required.

The other issue that springs to mind is that Dark Passenger is still just shy of being dps neutral in single target because of Slashing, but I personally think the solution to this is to keep it as it is for now, and just get rid of those awful 100% uptime buffs (Slashing/Piercing) in the next expansion.