I completely agree with everything you said about the appeal of snarry (hurray for power dynamics!). I'm glad you said it too, because I couldn't have put it so well.
also agree with the whole 'lack of resolution' let-down. The whole concept of the DH felt rushed and shoved into the story arc -- we spent 6 books leading up to a resolution that centered around the marauder era/forgiveness and prejudice/etc. and then... nothing.
Snape being devastated by his own feelings, and not in a woobie way. In a borderline-psychotic, helpless, out-of-control way. ohgodyesplease.