On the topic of dungeon finder. (I scanned over staff responses, it is likely I missed a key sentence somewhere.)
Wouldn't it be best to keep the dungeon finder, but maybe limit uses of it? I usually found myself doing some quests, grinding, yet running a dungeon or two each day, to spice things up. One could say go do PVP to get same effect, but for me PVP is too much stress and I rarely do it alone.
Possible limitations could be one specific dungeon run per day(lets say you can queue up for dead mines once a day.) and a set amount of dungeons per day/week. Maybe make a number so not every single dungeon could be done on same day, but keep the feature in.
I also understand scripting is hard, and figuring out why code works or doesn't can be a nightmare. My suggestion would be a middle ground for not having RDF and for having it. People who want to run more dungeons, can find groups and go to locations, while people that rarely do dungeons anyway, wouldn't have to be forced into active social aspect of the game. More shy people might find it unpleasant or intimidating. RDF would provide a "passive social" experience, and with limitations, could be a good distractions from questing.