I’d like to suggest that you create a new “Domains” page where a user will be able to see and control all of their domains that are registered through the CF registrar. By “control” I mean changing domain contacts, transferring the domain to other registrars or other CF accounts, changing nameservers (including using non-CF ones), etc. You know, the usual domain stuff.
The “websites” shown on a user’s dashboard should be logically separated from the domains registered with the CF registrar, and not bundled together like they are currently. This would provide a better user experience, and would allow the user to have a domain registered through the CF registrar that is inactive, i.e. doesn’t have a website associated with it. This way, the account dashboard of folks with a significant amount of inactive domains will be less cluttered.
This approach will also allow the user to explicitly declare that they want to transfer a domain of theirs to a different CF account, as opposed to the current procedure that is honestly tacky and probably opens the door for domain hijacking.