I have a Linux distro with separate /, /boot, and /home partitions, with grub2 installed in the /boot partition and a separate multi-boot partitioner manager in the MBR. This setup works correctly.

If in the particular Linux distro I move the root partition, of course keeping the same UUID for it, will grub2 still find my root partition and boot correctly ?

I know that under the old grub, if the menu.lst entry used a UUID to point to the root partition in the 'kernel' startup line, everything worked even when I moved my root partition.

Needless to say my fstab entries use UUIDs also to mount the correct partitions.

Yes, it should.

Grub2 can have problems when the partition where the core.img is imbedded is moved - not an issue in your case.