Renaming "Defaut-First-Site-Name" is not allowed in Samba4 (because the string is hard-coded in some places -- Andrew Bartlett, technical mailing list). It's however too tempting to do it on the Remote Administration Tools by Microsoft and as a result breaks the full installation.
This is a feature request. Be aware that this will take longer to fix. It will require full site support in s4.
Should be fixed in "master".
This is still an open issue, as any movement of a samba server between sites still requires additional work to update the rootDSE.
But we are *much* closer.
Well, the situation has improved - but the "dsServiceName" attribute (NTDS Settings DN) has still to be changed manually.
This is due to the fact that it's essential on the start of s4's DSDB library where we still cannot perform searches/lookups. So it is a bit hard to make it dynamic too.
This should have been fixed by the "dsServiceName" attribute in GUID format.