I'll echo a few points.
Keep the Druid
Though a Bst/Druid is a fantastic Combo. It is not a Name Killing Combo, as the Bst does not tank in the same ball park as a Knight or well geared monk. Thats not to say a bst/dru wouldn't tear up DN, but in a zone like HHK or FR the bst tanking abilites would be pushed to the limits pretty badly.
From reading your post on what you want to hit, I definitely feel a Sk/Dru or Mnk/Dru is what your looking for. Later on the Sk will provide a more solid tank then the mnk, but the Mnk is going to be more solid DPS.
Pal/Dru is a very nice combo, however for hitting names I think your better off with Sk or Mnk due to the ability to split pulls. Paladins can Pacfiy but thats not nearly in the same ballpark as a FD split.
As to DN, it doesn't take massive gear or AAs to go Rat Farming. Dragons will be out of reach for awhile, but those come fairly quick as well (at least the a dragon Shade).
Like someone mention above, DN xp is not about the single target xp.. its about rounding
up 6+ rats and killing them quickly neting you big Xp and cash.
A Bard/Dru is a pretty nice combo as well, definitely more finesse combo then a Sk/dru or Mnk/dru but has a lot of tricks up its sleeve.