As for what the hell is wrong with Sam, I think whether or not either Lucifer or Michael is still inhabiting him, Sam has no soul. The concept with souls happen to be an interesting with this show, this season has an example of both demons and angels making deals with humans in exchange for their souls. So that could be one possibility. There's also something to take into account that was mentioned back in S2 when YED had been talking with Dean about whether or not Sam had returned "right"; granted it could have just been a manipulative ploy because hey, demon. But we've seen Sam go from being Sammy to being this douchebag with a chip on his shoulder since then, so I'm wondering what if there's any significance to that statement or if I'm just reaching for something to make sense from the mess we've been getting lately.
New episode tonight, so hopefully we'll find out.
I'm sorry y'all, I'm still very upset about Caprica, that's what's been on my mind lately. I hate to even suggest it, but Syfy has treated Caprica like how FOX treated Firefly, and it depresses and pisses me off. ;__;