I have one of the DuoX chips in my Xbox. I forget the specific model. I know that powering the xbox up with the eject button supposedly loads the default Microsoft BIOS. Does this mean that I can do this to use Xbox live on the console without getting banned? I just want to confirm. Thanks.

I believe this is correct as long as your eeprom hasn't been banned and your hard drive is locked (which is has to be to load the M$ bios)

Yes you can use live with the retail bios which is loaded by booting with eject.