I know a bit inside ubuntu, (which is in my opinion the one to go for) but with the whole boot stuff.. no idea.
I have mine dual booted with win7. for me it uses the grub bootloader to make a bootmenu, so if you would have linux unplugged, i don't think it will boot.
not a clue though. Also, If you have ubuntu installed, you SHOULD be able to access any other OS you have installed. Wether it should be on the same drive i dont know.
I have both OSes on the same drive with diff partition.