A few comments :
1. linux driver CANNOT write to NTFS, only OVERWRITE.
2. There is a captive NTFS driver which use the native Windows driver(thunk/wrap in technical term) that can write to NTFS. This requires you to either detect where is ntfs.sys on the booting system or distribute it(copyright infringement)
3. it is not difficult to automate sensing the HD presence. Take a look at KNOPPIX's initrd and its init script.
However, I don't see why you need Xebian. Start with KNOPPIX would be easier if you want a full feature linux for PC. Afterall, you only need the script/program to do the lock/unlock for an Xbox HD. You don't even need FATX driver as that is not safe in 2.6 kernel which is needed for lock/unlock.
I'm giving a presentation on xbox-linux in march.. I was trying to find a really easy way to install linux on the xbox.. Xenbian would be perfect for this becuase it has all the files right there.. Plus it already support's the Xbox and the PC.. (rather than memory card or ftp helps if you xbox doesn't read td-cw's like mine)
Yes you can boot the xbox cd in your PC and it WILL RUN! While i was tring to make this work i thought hey why not make XboxHDM features.. So chimp your saying this isn't really possible? My UXE autoinstaller works fine in 2.6 it mounts and writes to fatX that isn't a good idea? I've yet to have problems with it.