[rich! @ etiviti]

regards to the drop down… the group loop (in theme forums/index.php) which only displays public groups needs another || check for:
groups_is_user_member( $bp->loggedin_user->id, bp_get_group_id() )

but if you disable bbPress buddypress component you won’t be able to post any forum topics

though, if a family site – why not lock down the entire site only to logged in users? (a few threads floating around here how to do that)