Some answers for you:
If your tsop's bios is corrupted, you can install an LPC modchip and you'll be able to boot your box. You will not, however, be able to boot with the modchip disabled, nor will you be able to fix your tsop's bios with an LPC modchip. For that, you need a 29 wire chip.
Once again, if you can get the xbox to boot with a modchip, you can do anything you want with the xbox, including unlocking the hard drive. From there, what you do with the hard drive is up to you. You can keep it in that box, and relock it, you can take it out and put it in another box and lock it to that one... You can take the thing out and put it in a computer and reformat it to work on your pc. You can use it for target practice. Whatever.
If you cannot get the xbox to boot, you're pretty much screwed on the whole hard drive thing. You can physically remove the eeprom and put it in a new box, along with the hard drive. It your eeprom isn't damaged, you should be able to boot up that drive. It that xbox is modded, you can unlock the hard drive there. Otherwise, you've got yourself a paperweight.
-Duck!
