I honestly think this sucks; trying to grasp how all the relationships would fall out was difficult, for many of the reasons you discuss above. I prefer the idea of Anna being pulled out of the pit by Dean, but it does change the dynamics of everything. However Dean as a "I'm so thrilled I get to eat pie again!" angel would be spectacularly awesome.

I adore the concept of fallen!Sam and angel!Dean looking everywhere for him; there is a power to that dynamic that really mirrors the canon show we know and love - Sam doing anything it took to get his freedom, including hurt the ones he loves; and Dean never, absolutely never, giving up. Well until 5.16. hahaha.

I wish my muse was more on track and I could write better than this drivel right now, I really rock on these ideas. So I guess you'll just have to write them instead, okay? OKAY! :)