1. This is such a big, fat strawman I don't even know what to say to it in response.
2. No, we're talking about balance in a game with a trinity system, not staying true to previous FF games. If this is the route you wanna take then its just going to devolve into "DRK should be a DPS" arguments.
3. No argument here
4. Is there something fun and imaginative about FoF or Berserk? You hit a button and you deal more damage for it. I suspect that you're not using it properly.
5. In single target boss encounters with no adds the lack of Quietus usage is moot because you dump the resource for it on Bloodspiller instead, so I'm not sure what the complaint is here. In dungeons you can spam AD until almost oom, hit Delirium/Carve and Spit, Quietus, more AD spam, Quietus... It gives us an AoE that doesn't cost mana and a way to dump our gauge in AoE situations, that's what its for and it serves that design purpose. You not personally liking the thematics of it is not cause for change.
6. Again with the straw man - I said our Grit damage was high relatively compared to the other tanks, mostly because of Bloodspiller ignoring Grit. What DRK needs in Grit is more defense, not more damage. We don't have a single native cooldown with an uptime higher than 10s and two of those are on a 3 minute or higher recast. Its almost like they gutted 80% of the job's personal mitigation, designed it up to 70 without fixing it, and then said "oh crap, this job is squishier than a cup of jello, we better dump all of its mitigation into this ONE skill and force it to rely on that one button for 90% of the fight"
7. MT/OT design is still a poor thing to adhere to. The OT's defensive tools go unused, and the MT's offensive tools go unused, and aggro cannot be managed/buffed effectively between the two through swaps.