Hey, jumping in is half the fun!

I agree with almost all of this -- except for the idea that it's "impossible" to behave any differently. Although I think I know what you mean by that.

I think your diagnosis of what Harry is doing, and why, is dead on target. But I also think it's possible to empathize and judge at the same time. I guess Harry's behavior is a function of a lot of things -- his experience of the Dursleys, which was not normal; his strategies for protecting his own ego, which may be necessary but aren't always ideally functional; his judgments about Snape, which may be naive or incomplete. It's good to understand all this, but it's also good to evaluate it, and to consider whether he has the capacity for growth or change. That's the only reason I'm judging him so harshly -- because I think it's useful to have a clear sense of what he's doing wrong, of how his limitations are affecting his ability to deal with problems like Snape.

I babbled on at ridiculous length to pilly, below, because s/he made so many specific points, so I'll just cross-reference that and not repeat it. :)