fedora 18 64 installs fine on the 32 gig thumb drive i have it on
usb2 is SLOW though
and the first update if using usb2 will take at least 48 hours of non stop running
firewire or usb3 would be better
2. Be able to boot it, without destroying my Mac system and the software on it.
on an external drive ,no problems
just take EXTREME CARE not to install grub to the apple MBR and install it to the external drive !!!