What lies? Other than the types of lies that a typical teenager makes, I don’t remember any really big lies. As for desire for vengeance, he is obviously angry at Voldemort for killing his parents, but unlike Voldemort he never allows his anger to overcome him. He never once said or indicated that he desires vengeance. As for his anger, he is again angry that his parents have been killed, but it also does not consume him. He is portrayed as living a pretty happy life. We all get angry at times, as does Harry, but I’ve never read anything about him being conscious of a constant nagging anger.
Obviously, Slytherin was the house of outright dishonor, intimidation, and domination. Gryphindor had to cut a lot of corners to counter Slytherin, which was also a point that I think Rowling tried to make.
I loved the books. But--I wouldn't buy a Ouija board for any kid.
Harry was constantly angry during most of Order of the Phoenix. He asked Sirius if he was turning evil. He cast an unforgiveable curse several times out of a desire for vengeance. He manages to overcome all this partly by realizing that Voldemort can use that anger to weaken his bonds with others.
I must say that the complete lack of trust the central characters have in most adults occasionally bothers me. For example, what was the point of lying about the troll in the bathroom incident? Minerva would have been proud of the boys for going to rescue Hermione, without Hermione being in trouble too. I also think they could have told her why they were up at the top of the astronomy tower. They were simply trying to keep Hagrid out of trouble.
Harry could have saved himself and others a lot of pain by confiding in some of his teachers more often. But really, there wouldn’t have been much of a story if they just followed the rules and sat in the common room all the time. :)