Help me in making a fighting game

1

I am trying to make a classic 2d fighting game. And before I begin I have a few questions:

  1. What is the best way to do collisions between fighters?
    The simplest way that would work is to check distance, enemy stance, and direction of enemy! Or I can place invisible movieclips on arms and legs, and hitTest against those. What is your suggestion?

  2. What and how do i use sounds to keep the file size low (fast loading)? Also what format of sounds is preffered? wav or mp3?

  3. Though i will make customisable controls, but still, what will be a preffered default control set?