If you want to try and test that much different distributions without putting each on it's own partition, then I would rather suggest you install vmware or vmware-player. That way you can boot each iso-file as a virtual machine. You can also use VirtualBox or Quemu, but so far I had the best experiences with similar attempts by using vmware.
Having all those distro's on a single partition - even worse: a FAT32 partition - is something that I doubt that it will work, though I don't rule out that it is maybe possible somehow. It will certainly be complicated and painful.