You will lose all info on the F drive. But you will free up 67gigs too (200 gig right).
You have to use Avalaunch or XBMC (they have a way to look at each file were Evo X does not) to launch XBPartition's "default.xbe". It wont pop up like a game or app, which it shouldnt anyway. If you leave it on the box and somebody screws around with it, then Poof gos all your work.
Avalaunch and Xbox Media Center are other Dashboards. I recomend gettting them and loading them on your xbox. If anything just XBMC, but I like to load both. Avalaunch is smaller and will load faster if your just gonna use them one time.
The "default.xbe" is the launching program of all xbox files. You want to fire off a game/app, then you click the "default.xbe" of the file, and it will start up.
Im not really for sure what you mean on teh third question, but if its what I think your asking, you can put the expolit in threw FTP. I just use an Xbox memory card to put them on boxs. Just copy the game save in the memory, then fire up the game to run the xploit.
Questions is how you learn. We were all there at one time or another.
I have no clue on the USB jump drives. I do know
llamma.com used to make them for a decent price.