All I really want to be changed for DRK is a way to make the off tank TP situation more bearable. Very minor mitigation buffs aside (maybe 5% overall?), that is my biggest complaint with the job.

I should not have to stop hitting an enemy after two minutes (2:10 if I'm lucky with TP regen I guess) to spam my magic ranged attack in melee distance on anything. If DRKs lasted 3:15 or 3:30 of sustained WS on an enemy while OTing that'd be much more acceptable.