Just wondering, this is the first time i have used a xenium, when i boot up, the xenium os comes up, if i then select TSOP, it boots the original bios, will this let me go on LIVE?

YES as long as you boot your retail bios you will have no problems getting on XBL just make sure your hdd is locked

yer, jus wanted to check coz i installed the chip for a mate and he wanted 2 make sure that this was the right way to turn off the chip.
Cheers