Not quite true, actually. You will have to change your gamertag if it's already in use, but you won't lose any Achievements or anything else. I had an offline profile for about 8 months or so, and had to change the gamertag when I finally registered and went onto LIVE. No loss of anything.
Yup. You'll have to have it LIVE-enabled, though. And make sure you buy for the right region - US or UK.




