It's one possible theory, though a farfetched one. They haven't done anything in a long while, and this doesn't fit with anything Zachariah did or what Raphael might do. Wouldn't rule anything out, though. If this is angels, however, I won't be too surprised
Few good ones but most of the angels are pricks, especially since they want to restart the Apocalypse. Unfortunately there hasn't yet been an update on that front.