Drg for the entire run, yes.

I've killed Miser before she moves, but I dont remember which jobs we had because it wasnt with my LS, some weeks ago. Maybe there was another Drg

I haven't done 17' yet, but my LS should be able to pull it off. I'm the only one at this point of the quest in my LS and we only tried 3-4 runs. Our best run was 19', we lose time against Miser because many members have good blm stuff but not on their melee jobs :s

Indeed Drg on Miser can be weaker because of how Power Surge works, but I think it's possible to keep it up after coincounter all the way to Miser if everything goes smoothly.