Yeah, you'll have to use a tripod, or have some kind of way to get the camera to move exactly the same way for each clone. Though possible with a greenscreen, it may be best if you need the people to be moving, have the actiors move in their individual shots, but not the camera. Hope that makes sense.
For the cloning, you'll have to import each clip into your FX Home product, trim it down, position it, and key out the green, if you need some help with cloning, you can see my tutorial here
For greenscreening help, please see my greenscreen C-Lab & vision Lab tutorial here, here,
Though you proably know it already, I decided I should incluide those basics on lighting and keying anyways.
As far as layers go, each clip og greenscreen clones would be a different layer. You'll want to cut them all to be the same length and then add loops or additional footage to make it longer.
I hope that helps you out some!
Last edited Mon, 3rd Aug 2009, 11:42pm; edited 1 times in total.