Sicilian Surprise 2... f6

This is one I haven't seen before.  It looks like a mistake, but I wasn't sure how to answer it.  I'm sure that the pawn they lost was just a mistake, since it doesn't seem to be a good gambit.  Some of my moves were probably suspect, as well.

if not for blacks rating Id say it was a mouse slip and they meant e6

The database I use has 5 games in it with this variation, with a positive score for black (Including Bent Larsen mating someone in 6 with white, he was also the only player to play 3. d4). Fairly sure those black wins were not at the master level though..

I really don't like the weakening of the kingside.

Mouse slip or not, it doesn't matter.  Black's motive is not the question.  The question is how should white proceed after f6 as well as what to do with the knight in the next couple of turns.

I'm a bit confused here.  A positive score for black seems to imply black does well, but then you say that Larsen mated someone in six with white.  Do you mean that black has a negative score?

Black won 3 games (somehow), white won 2. One of the white wins was a mate-in-6. The formulation of that sentence might not have been the best :p.