Parr,
Yes, that should be pretty simple. In the JFBConnect -> Profiles area of JFBConnect, there is a setting called "Show Profile Fields:". Set that to "None". Then, when registering through JFBConnect, no JomSocial registration fields will be shown. You'll still need to leave the JomSocial profile plugin enabled with the "Import Avatar" setting enabled.
Finally, in the SCLogin module, there is an option for "Registration Component" which you can set to "Joomla" so that the redirections from that module go to the Joomla registration instead of JomSocial's registration.
Hope that helps, but if not, or you still run into issues, just let us know!
Alex