He he : this "Christian" is quite dangerous for a 1100 player - well it shows that computer ratings are quite different from human players - anyway, back to your game
I agree with you that 5.Bxf6 looks interesting : after 5...gxf6 6.cxd5 exd5, black's pawns are completely crippled. However, it has the bishop pair and the open g-file on your king-side, so maybe it won't be that easy.
I agree with your 8.bxc3 choice too.
9.Nf3 may be okay, however I like 9.Bd3, maybe with Ne2 to follow - I think it offers better protection to your king. I understand you don't want to lose a tempo if white plays 9.Bd3 dxc4 10.Bxc4, but I don't see how black can really take advantage of it. As for 9.Bd3 Rg8 10.Ne2 looks okay, as after 10...Rxg2 11.Ng3 it seems the rook is trapped.
I don't agree with your reasoning for not playing 10.cxd5 : the position is getting open, and speed is essential here. I think 10.cxd5 Qxd5 11.Bd3 or 11.Rd1 are really worth a look.
Even if it looks dangerous, I would consider castling before starting active operations on the Q-side, so 12.0-0 - I can't see anything special for black here (ie. 12...Rg8 13.Qxh7 or 13.Nh4, 12...Qg4 13.cxd5)
I agree with you about 14.Ke2 : I think it was better leaving all your pieces free to come into play
after 16...Rac8, despite your extra pawn, I think black is much better, thanks to its attack on your king...
I think 17.e4? is a fatal mistake - opening every line in front of your king. I would have tried something like 17.Rd1 or even 17.Ke2 to get those pieces playing.
You don't say anything about 18.exf5 - was it losing directly ? Admittedly, something like 18...Re8+ 19.Kd1 Rcd8 looks dangerous, but...
Your resignation looks normal : black took full advantage of your king's position : 19...Rxd5! is a great move.
I recently lost a blitz game to Chessmaster personality Christian, rated 1181. I thought to myself that I should easily be able to beat him in a slower game since I on this site have at least 1600. That wasn't the case. Even so the game turned out to be quite interesting and I really took the time to play the right moves all the way through. The time control was 40 moves in 2 hours and then 1 hour additional time for all moves after that, although I think the game didn't last more than 2 hours anyway. The reason for these time settings is because I need to get used to playing under such circumstances since those are the settings used for OTB rated games where I live. I recently lost my first OTB match to a 1412-player so I think I need practice in that area. Please help me improve :)