Hi,
1) I am not sure, but I think it should work (but you have to check the config afterwards ;-) )
2) What exactly do you mean with migrate the domain? If you think of it like "I move the AD to another server and shut the old ond off" then, yes, it is possible. Link in the Windows world you have to move the FSMO Roles to another AD server (look for it in the SaMBa docu).
When the "old" server has also a (e.g.) DHCP server running, therer would be some additional steps to do...
Regards
Thomas