As far as I can make out, Anna was fallen, but then found her grace again which in the Supernatural world is a physical object. She's now a proper angel again.

Castiel rebelled against heaven to save the Winchesters and was punished by an archangel, but then reinstated. Sort of. Ish.

I enjoy Supernatural, but I must be honest, mostly as eye candy. I haven't really got into the fandom as Wincest seems to be the most popular pairing. I haven't got anything against slash, but incest is too weird for me. Plus, in canon Dean is such a womaniser that I just don't see him as gay, even if he does spend every other episode crying.