Rhyn,
I'll be sending you a PM directly after this with a test release of the 4.0.1 profile plugin for JomSocial. It should correctly detect when a multi-profile is set for Admin Approval and block the user so they can't log in. We're not releasing this to the download area yet as we have little experience or feedback with JomSocial's admin approval setting, and would like your feedback.
Just so you know, with this plugin, the standard Joomla new user emails are still being sent. So, for the new user email, you may want/need to update the text in the language file to let the user know that the user will be moderated. Once approved though, the normal JomSocial "Account Approved" email will be sent.
Beyond that, if you run into any issues, let us know. There's some trickiness that we had to get around in this plugin, and we'll be improving the whole process in the JFBConnect 4.1 release, due later this year, but hopefully, this gets you going now.
Thanks,
Alex