I would completely buy Alec acting like a wary animal, but the writer acted like he'd leave just because he's sort of a jerk. And I like your analogy of Alec and a wild creature. I think it really fits. Instead of biting, he snarks as a way to keep people from getting too close.

When I saw Alec playing the piano I was very impressed with whatever hand model they used, because it was seamless! It really looked like Alec was playing the piano. And then I find out it looked so fantastic because Jensen actually learned the pieces... I'm definitely impressed. *g*