I like it. The story kind of reminds me of Elementary Calculations. In that one he acts a bit like your Harry and ends up in Ravenclaw. Actually I'd say raven claw is best considering your threw Slythern out the window due to the fact that he thought Hogwarts was B.S. till the professor showed him the fact that magic is real. Also he has no Hufferpuff tendencies due to the fact that he had no friends in school and liked it that way. Maybe Griffindor due to he seems not to be afraid of doing some thing like kicking a boy twice your size in the nuts or calling BS on the school. So it's got to be the Ravenclaw or the Griffindor . If you go dorks I doubt the he would make any friends since they don't seem to that fact based other than Hermione. Ravenclaw might be the best due to him believing facts not word of mouth.