I'm not familiar with Android (and Linux), but from what I've heard until now it is generally not possible to set up multiple user accounts within the OS itself. The problem is, that for a tablet every family member should/wants to have it's own account for e-mail, browser, files, etc. Also someone doesn't want to sniff others in your own accounts...
I also heard that it is already possible to install a bootloader and different OS (or not?).
So my question is: Wouldn't it be possible to install the Adam OS into as many different partitions as you need user accounts and select your "profile" on boot? Also good would be, if the partitions can't be accessed from the others, while within your profile, so it is not possible to accidentally delete some files or whatever.