Do you mean the permissions that are asked of the user in the Facebook login popup, or the registration fields for your site?
For the registration fields, please install the JFBConnect - JomSocial profile plugin in the profiles zip file that is part of JFBConnect. Enable that in the plugin manager, and then configure it in the "Profiles" section of JFBConnect. You can select there to have all, required, or no JomSocial fields show during registration. You can setup information to automatically be imported into JomSocial from Facebook.
Hope that helps, but if you're still running into issues, just let us know!
Alex