Game I played on Saturday
"Post Mortem, my opponent claimed that even if I hadn't blundered then my doubled, isolated f pawns would be enough for him to win. What do you guys think?"
Maybe if he's Karpov... :) Sure, they're a liability, but to claim that position is a win for Black is a bit of a stretch.
Btw if 12 Bg4+ there's 12... f5 (in the line you give Black is dead in the water after 14 Bxd8).
Thanks, it's good to know that my blunder cost me half a point. Btw, thanks for pointing out the error in my analysis on move 12.

I don't understand your comment for your 18th move.
"18. Rxd7 (Better was Rg1, which wins a pawn.)"
Your knight hangs if you play Rg1. Part of the problem you were having in that middle game is that the rook was pinned to the defense of your knight for so long. There aren't even any tricks with 18. ... Rxd5 19. Rgxg7 because of 19. ... Rd1#.