I agree with most of the points here. Coming from a level 50 Paladin (pre-HW), DRK seems unfocused and a bit weak overall.

My biggest complaints would be that multiple abilities are underwhelming (Dark Dance, Delirium, Shadow Wall, Living Dead), and that there is no specific focus for the job. While it seems like it was designed to deal with magic mitigation and managing MP, it doesn't do great in either (there aren't any situations in which a DRK would be chosen over a PLD or WAR).

My biggest problem so far (beside TP) is Dark Arts. For the cost, I can't really justify the effects gained (especially with the MP drain bug). I feel like this should be the main mechanic of DRK, yet it feels lackluster overall.

At any rate, I'm only 55 on DRK and by no means a pro. So maybe I just need some more practice.