1. Does Dumbledore come back?
Not resurrected, but Fawkes and the portrait will be active and represent him.
2. Whose side is Snape on?
Harry's. (I was very precise about this after reading some fanfics in which Snape is working for Harry's benefit rather than being 'Dumbledore's man'.)
3. Who dies?
Voldemort, Ron or Hermione but not both, Neville or Ginny but not both, Snape, Lucius, not Harry, not Draco.
These were all wild-ass guesses except Voldemort, Snape, not-Harry.
4. Does Harry get back together with Ginny? Do Ron and Hermione end up together?
H/G: Yes but ew. R/H: no because someone's dead.
5. Who gets forgiven or redeemed?
Snape does, Dursleys don't but it is irrelevant to the story, Draco remains ambiguous, Voldemort and DE's not individually named don't.
6. Is Draco Marked?
Yes, by the end.
7. Was that the Horcrux locket they saw at #12? Who had it, Kreacher or Mundungus?
Yes, and Mundungus.
8. Was R. A. B. Regulus?
I didn't write this question down, I snagged it from ravenna's post, but I'd have said totally yes, that introducing a new R.A.B. would be lame.
9. What was the real reason Albus trusted Severus? Was it, as was said before, because his remorse over the Potter's deaths was real? Or is there another reason? Something we don't know?
Another Unbreakable Vow.
10. What about the life debts? Will Peter Pettigrew's life debt to Harry be important? Was Snape's to James passed on to Harry, or not, since we don't know how life debts work?
Peter's will matter and be paid off; Snape's, if relevant, will be answered by his working to defeat Voldemort and by his death.