Good point with the first name thing...i'm not sure what would happen.
Now that users can create their own facebook url (facebook.com/username) it should be set up where you have to use your facebook url username to login using facebook connect however not everyone has that set up and not sure if it's still available on facebook or not.
Maybe just using their email address...no 2 email addresses are the same and in order to log in to facebook you need to login with your email address.
The bottom see more line is i do think something could be done about it weather it's from facebook or boonex...i strongly think that facebook would have to include that though.