To make Jami more user-friendly without a registered username, you could transfer the profile names after connecting using the 40-character ID and display the names instead of the IDs. In addition, these display names should be editable (e.g. if you have more than one friend called Bob).
I believe profile names and photos should already be automatically transferred even for accounts without registered usernames. Editing these, however, is unfortunately not supported at the moment, but it is a known feature request.