Glen,
I can't imagine a reason or extension that would be automatically setting that value. The option also shouldn't be exposed to the user on the front end. I'd check the User plugins you have enabled to see if there's anything 'odd' there that might be the cause. It could be any type (system or other), but User is a good guess to check.
Beyond that, the only thing I can suggest is removing the admin email. It won't affect the email the new user receives, so that shouldn't be a problem. To disable, you'll need to edit the /components/com_jfbconnect/controllers/loginregister.php file. About 20 lines from the bottom of the file, you'll see:
// get all admin users
$query = 'SELECT name, email, sendEmail' .
' FROM #__users' .
' WHERE sendEmail=1';Simply add the following line directly above that:
That will prevent all the code below there from running, which is what sends the admin emails.
Finally, for the new user registration being sent to a registration form, that's normal with the way you have JFBConnect configured. If you want the automatic registration (no forms) you should change the "Registration Flow" in the configuration area of JFBConnect to "Automatic".
Hope that helps, although I'm still confused as to the actual cause of the first issue...
Thanks, and good luck,
Alex