Re: Should flash drive have FAT or ext4 on it before running LiveUSB creator?
There are other reasons why a F16 schtick won't run though. The USB boot system doesn't seem to be very robust and doesn't work properly on all hardware.
I just went through a long series of trial and terror and eventually used a DVD to install to a USB drive on my Thinkpad. Just copying the ISO files to a USB device would not work (and neither would any of the other utilities for making bootable USB sticks), though the same ISO files would boot the same machine off a CDROM (and those unbootable USB sticks would likewise work on another machine).
I had to select the 'Force /boot to be a primary partition' option, to get the disk to boot. I also had to disable SELinux, since that would also randomly cause the system to hang when running off a USB disk.
The bottom line is, that you should eventually be able to make it work, but you may have to run quite a few experiments.