I always saw him as a regular, decent stage magician who got caught up in a romance with someone who showed him real magic. His communication with Harry post-death is perfectly acceptable for a regular guy, whose only cosmic importance were in his two most prominent relationships: Harry and Margaret. In fact, it'd be really fitting for Uriel to approach Malcolm, mainly because he was just a guy.
It was one of the reasons I liked Butters so much before he picked up the Sword; he was just a dude trying to do the right thing, with enough sense to realize that he's really far out of his league. I haven't read his Knight short story yet, because, as I've said in other threads, I'm not gonna buy a short story compilation for the one story I want to read, so I don't know what he'll be like as a Knight, but I really liked the Regular Guy theme (one of the reasons I liked the Codex Alera books pre-Princeps, though I like the other two for different reasons).