I think you now need to use udisks to mount and read/write to floppy disks, which does make life a bit difficult, as I have yet to find a simple way to mount them in my old desktop machine by simply using nautilus.
I have very little use for floppies now, but I did when I purchased my machine some while ago, and therefore if I need it now I use aliases of
in my hidden ~/.bash_aliases file to speed up the mount and unmount of the few floppies I have left with things on that I need.
alias fd+='udisks --mount /dev/fd0'
alias fd-='udisks --unmount /dev/fd0'
Note that this is not a typo; the commands really are "mount", and in particular "unmount", as opposed to umount for the normal unmounting command.
I am not sure about the mac format situation, but I do know that mac filesystems can be read by Linux, though you may need some of the hfs packages installed.