After quickly going through this game I wouldn't criticize any of your moves. Of course there are alternatives but I couldn't find anything radically better. I believe 8. Qe2 is best, because e5 pawn is a very useful central pawn. This pawn hampers blacks development by stopping him from developing his knight to f6 and also discouraging d6. Also, after 8. Qe2 black must spend a tempi moving his bishop and white is happy to castle long. Basically white obtains a big lead in development in an open position without any sacrifices.
15. Nxf6+ seems to be simple and strong. I see a promising alternative in 15. Bxd6!?. After this black has a) 15... Qxd6 16. Nxf6+ +-, b) 15... Bxe6 16. Nc7+ Qxc7 17. Qxe6+ +- and c) 15... cxd5 16. Qb5+ Bd7 17. exd7+ Qxd7 18. Qxd5 +-. But this is just an alternative move and probably not really better than 15. Nxf6+. White just has such a big lead in development that all kind of tactics work.
In the game continuation you mention 15... Nxf6, but white preserves big advantage after the simple 16. Bxd6, when black will find it difficult to finnish his development. 16. Bxd6 would also be good in the game after 15... gxf6. After 18. Qc5+ white surely has a winning attack (18... Kg7 19. Rd3).
I believe blacks biggest mistake was 3... Bd6? This is a really clumsy square for this bishop.
i think i like this opening. it was a 10 min game and i was running low on time at the end. i think the only reason i won is because of his blunder at move 18... Ne7 (i think Qe7 would have been better for him [nevermind: that would lead to 19 Bd6 winning the queen]). also i think 15...Nxf6 would have been better for him, so he could use that g pawn to block the light-square bishop check.
any thoughts on my moves? i'm not sure if 15 Nxf6+ was the strongest move there. i have a hard time analyzing my own games. i think 8 Qe2 was weak as well. what would have been stronger at move 8? light square bishop out and give up the pawn for development and castling potential?