John,
The user registration/login aspects of JFBConnect can be deactivated pretty easily. Simply not enabling the JFBCLogin module will prevent the Login With Facebook button from displaying, and even if a user figures out how to login through Facebook with direct Javascript calls, if you have user activation enabled, we respect that.. so new accounts simply won't be approved.
We have many users who use JFBConnect just for the social aspects or Page Tab integration, and completely ignore the login parts.. and others who are the complete opposite. We try to make it easy to integrate with Facebook however you want.
Hope that helps, but if not, just let us know if you have more questions. As always, we have a 30-day money back guarantee and just launched v4.0! For more information, see:
www.sourcecoast.com/blog/extensions/jfbc...atures-you-need-this
Good luck,
Alex