Eupfhoria,
1) JFBConnect uses the "New User Registration Group" setting within Joomla itself. That setting can be found in the User Manager by clicking on the "Options" button in the top right. If that setting is correct for the default group you want, and JFBConnect is still not adding the user to that group, definitely let us know.
2) Email Not Verified ugly message - Yes, you can customize this, but it will take a quick hack. Not sure why it's still like this, but it's hard-coded into one of our files. If you edit the /plugins/jfbcprofiles/communitybuilder/communitybuilder.php file and search for that message, you'll see it in there. I've added a task to our bug tracker to properly use the CB language file for this message in the future.
3) There's no way to use the CB registration flow while the user is registering through JFBConnect. CB has a very unique registration process that we can't hook into to do what we need to (communicate with Facebook, pre-fill fields, get the new user's ID, map the two accounts together, import avatar, hiding fields that are mapped, etc). JFBConnect has to use it's own registration form which works with all the systems we integrate with. For the 4.2 release, we're planning to greatly enhance the profile integration features in a few ways, but that release is a few months out.
With the JFBConnect registration flow, your users should see the standard CB icons (registered, profile, blue 'i' tooltip icon). When hovered over the tooltip, the CB description for the field will be shown. If you're not seeing that, let us know, as something's not right there. If you want to show all fields (not just the required ones), we can help you do that. However, right now, JFBConnect will not pre-fill them in.. we do the import of user information after they registration process completes.. pre-filling is something that will be in the 4.2 release.
Hope that helps explain a little. Certainly if you run into other issues or have questions, let us know!
Thanks,
Alex