My question concerns 7. Nf5. It's a little counter to what I've always heard about chess because it allows doubled pawns and removes a pawn from the 2 center squares after 7... Bxf5. I did it because I like to get the 2 bishops early in the game and because it just "felt" like a good move in that it gave me a lot of space in the center.
I think it was a dubious move. Indeed, as you say, it gives you doubled pawns. After the exchange Bxf5 exf5, if you were to take all remaining pieces off the board, the pawn endgame would be lost for you.
Yes, it does give you the two bishops, but the pawn structure is more important. You have an extra piece (bishop) on the light squares. But Black can, after some moves, play c6 and d5, when you either retreat it to d3 where it stares against the own f5-pawn or to e2, where it isn't doing anything noteworthy.
It probably felt like a good move because it was forcing. You got the bishop pair and an inferior pawn structure by force.
Your comment about the move giving you alot of space in the center confuses me. First of all, the sequence (Nf5 Bxf5 exf5) reduces your central control (= space) because your sole remaining center-pawn has been removed. Secondly, you allowed black to exchange a (undeveloped!) piece, which reduces his space deficit impact.
Having said this, I think there are several moves which give white a slight advantage. For example, Nxc6 isolates black's a-pawn. Or you could just pursue development with O-O.