Q+N vs. R+2P ending.

Here's my latest game on FICS, a 2 12 blitz game that went 70 moves. It featured some neat tactics and fairly bizarre situations before settling into an ending where I was left with a Queen and Knight against a Rook and two connected passed Pawns.

In regards to the ending, I'm particularly curious as to whether I had a swifter way to win the game, as it ended up taking 27 moves, and I'm not convinced I was forcing much of anything. It's an endgame I'm fairly unfamiliar with. 

Comments on opening and middlegame play are welcomed too, I've tried to provide some rationales in my annotations, which are brief but hopefully illustrative.

I realize you don't need to hear this but you missed a clear rook grab starting with

47)Qe4+ Kc5

48)Qc4+

how can the rock win the queen,this show how defence power both of them clearly

nice job