Christian,
That's a perfect solution *if* you want all users that register to be in the same user level. JFBConnect will use the default access level in Joomla to register all users, so what you did will definitely work.
If you want *only* users that login through Facebook or LinkedIn to be in a different group from users that register normally through Joomla, you'd need to make a slight modification to our code.
If you have things working how you want though, then you should be set.
Thanks,
Alex