I honestly had no idea there was White Collar acefic - the only interesting thing I knew about that fandom was the poly with the FBI agent's wife. But I guess I can see where ace!con artist is coming from. He flirts as part of the con, by extension it's possible that all flirting is a con... something like that.

But god, no, I can't see ace!Cas, not since season four. And back then, that could just been the lack of personality speaking. (I also can't really read Cas fic at all anymore, because I've been burned by too many bad characterizations in either direction - he's either totally socially inept/Sheldon Cooper-like, or he's done ~everything~ for Dean, so why won't Dean do the same for him?? I shudder to think how those writers would tackle ace!Cas.) I guess compared to some of the more hedonistic angels he seems non-sexual, but I definitely read that more as celibacy/chastity/general restraint, rather than disinterest.