Buddypress – New user type with no profile and can’t interact but can be admin of a group

If you want them to be able to choose the type
You’ll need to write your own registration logic

After that check via get_user_meta() to see if they have a certain permission

if they can do xyz and allow accordingly. I’ve done custom user types before for a plugin i wrote.

There’s no build in roles in BP AFAIK but a lot can be done via actions and filters, does require some coding skills though.

Let me know if you need more help