Some points in this story are awfully WAFFish, and others tend towards a severe Gary Stu'ness which was a turn off in reading. However, parts of it were quite funny, like the duel using houses. I laughed hard at that bit. I hope in future you'll be willing to write an HP story which DOESN'T require him to be massively out of character, massively overpowered, and massively well informed. Consider it a challenge. How can you manage to bring HP through all these trials and tribulations without cheating? After all, how great of a hero would Harry be if he's massively more powerful than anyone else? Answer: not much. It would be good if you applied your talents/education in history and looked for a more objective method for Harry to accomplish his goals in a more believable way, with the least outlandish advantage. Something as small as studying 10 more minutes a day would probably be enough for him to defeat Tom. Find a Butterfly Effect without the massive power-ups and go from there.
Try my first schnoogle story (Relations/Price of Peace). You can easily argue I wrote too much, so there probably something somewhere that would appeal to most fanfic readers