(adsbygoogle = window.adsbygoogle || []).push({}); You know the E0000xxxxxxxxx that you get of your xbox which is your profile. If I uploaded this, could someone redownload it, put it on a memory stick back into their xbox and sign in?

Yes they can. But this is in the wrong section :p
I'm pretty sure it's possible.

Yes, however you might come into problems then signing in on your own XBOX.

If this problem arises, delete your profile off your XBOX then recover it.