Touchscreen Questions From A Newbie

I'm looking to do something with Flash on a touchscreen. I want to be able to
press a button to initiate a transformation. I reckon that my background could
be an EPS or Tiff file, it wouldn't matter. But the series of flash movies
would rest in their respective places, each with their own buttons. Please
correct me about anything I've just written.

A couple of questions:
1) Would the movies have to be FLV or can they stay .swf?

2) Since there's no "over" step for the buttons, would they just have a "down"
frame and that's it?

3) When working with large interactive displays, how do you load your file?

Any other insights you might have on working with touch displays and flash
would be greatly appreciated.

Thanx