Its exactly like every DRK thought.

[Valknut]

It might address the survivability issue, but it'd only be a bandaid fix.
Dark Knight needs some serious rethinking about his gameplay flow and how its mechanics interract with each other.

Giving it sustain will just make it less awful, but still boring to play.

I disagree, I only play PLD and DRK at 90, and PLD in comparison to DRK feels slow, methodical and very boring. I don't play at a high level, but on PLD my mind set is " Keep dot up, keep FoF on CD, Keep Req on CD" When I fail to do any of those it just feels bad, and boring. Despite it being clearly much easier to survive on during expert dungeons, or the random extremes I do get around to playing.

Drk does have problems. It feels like a machine gun for 30 seconds and then it feels like your fumbling to reload your 6 shooter until the next pull. One of the things I would suggest is to make sure DRK gets full mp between pulls. Hell give it to all tanks, I doubt it effects any of them like it effects DRK. That would keep me playing DRK in dungeons. On bosses... God DRK feels awful, I don't play with buff window timings or organized play. So its all fire and forget on CD, and " God damnit I burned all my MP, and can't TBN this mechanic" its incredibly unsatisfying.