I am playing as black.

1. e4 c5
2. Nf3 d6
3. Nc3 Nc6 (my opponent tried to mix it up, so I decide to do the same.  Although I feel 3. ...Nf6 is stronger, Nc6 is not bad)
4. Bb5 Bd7
5. 0-0 a6
6. Bxc6 Bxc6
7. d4 cxd4
8. Nxd4 Bd7
9. Qe2 e5!?  (I had a feeling this move would lead to complexities in the position as my oppponent rarely plays against the open sicilian)
10. Nf5 Nf6 (I was seriously considering d5.  I invisioned 10. ...d5 11. exd5 Bxf5 12. Qxe5+ Ne7 13. d6 Bxc2)
11. Bg5 Bxf5!? (I am not sure if this was the correct move or not.  I know it will later weaken my light squares, but the knight seemed fairly powerful/well placed on f5)

Now, here are my questions. 
Is 3. ...Nc6 that bad of a move, or does Nf6 clearly outweigh Nc6?
Is 9. ...e5 justifiable, or would e6 be more sound?
Would 10. ...d5 be better than Nf6? 
Was Bxf5 a strategical error, or is it a sound trade?

Thanks. 
By the way, I later went on to win the game.  It was a drawn position, but white went on to try for a win, which ended up costing him the game.