yes you should be able to...put the old hard drive on then put the flash drive in and go to the saved game file in the hard drive and copy it to the flash drive then take out the old hard drive and put the new one in and copy the file from the flash drive to the new hard drive and it should work (to get to saved game files go to the start menu a.k.a. xbox360 dashboard and go to the My Xbox tab and go all the way to the right and you should see system settings...then go to memory then games and look for your game and click on it and you should have 3 options 1. copy 2. move 3. delete and you can either move it off the hard drive or copy it...your choice hope i helped :) (you can also use a data transfer cable to just go hard drive to hard drive which would be alot easier)

A external usb hard drive? Plug it into another usb port? If they're all filled up a splitter might work but I'm not positive. Otherwise you're screwed.

You can download games, themes, and avatar items to a flash drive so yes, it is like an external hard drive.

Yes, this one is thin enough to fit.

No, there is no way to save gameplay footage on the xbox 360 to a flash drive.