I want to associate sub.myorg.org with my nation, and then later change it, and have myorg.org proper associated with my nation. Is that problematic?

Can a subdomain like nb.example.com even be association with a nation?

Removing the subdomain question, what if I want example.com associated with my nation, and then three months later I want foo.com to be associated with that same nation (no longer example.com).

In all cases, redirects are unlikely to be part of the solution. I am talking about switching the main domain for nation from domain to another, not merely redirecting.