I have 4 machines; all multiboot.

I want each machine to have full rw access to file shares on each other machine, AND, full rw access to the other partitions on the same machine home folder for UNbooted OS's.

I imagine Samba will NOT handle all these configurations? What else do I have to do, so that, for example, if I have 2 machines on, and I boot up a third machine in another room, it will auto mount the other 2 machines' shares, and it export it's own shares to the other 2 machines?

I want also each machine to have full rw access to shares on the UNbooted partitions of each machine.

You will need to have the filesystems mounted to be able to access them. If you have the same UID on each machine & each distro then access isn't a problem. If the directory being shared has "o" other read/write permissions, than it would be possible for other users to read & write to the share. If on a remote machine, you don't, you can still use the credentials of the user on the remote machine.

The mount.cifs manpage has details on the options you can use, but don't put the password in the /etc/fstab file. Use a credentials file instead that contains the domain name (if you use a domain controler), username & password.

Using "Security = User" & mounting shares using the cifs filesystem, I'm not certain whether username & password are enough. This is because cifs unlike smbfs supports permissions & acls. You will need to experiment.