You can't simply join, as in "travel to the capital and pledge yourself to the realm, leaving friends behind". That option is not available for the Zuma capital. The only other option is switching duchies which as Artemesia and myself have both pointed out, is considered by Tom to be exploiting a bug.
If you wish to surrender to the Zuma, just send them a letter saying so. Have you tried that?
The problem, Vellos/Glaumring, is that all you see are problems; you need to be looking for possibilities. Perhaps you need to pause your DWI characters for a while, and come back when your attitude improves.
Poll