Q: I can only disable comments via the options menu. There does not seem to be anyway to control it. How can I restrict comments to registered users?

A: There is no particular option for this case when using the built-in RSFeedback! commenting system. However, you can achieve this through template overrides. This procedure is explained here.

The file you need to perform template overrides is located under this path:

/components/com_rsfeedback/views/feedback/tmpl/default.php

Open the duplicate used for template overrides and search for:

<?php echo $this->comments->form;?>

Replace the above line with:

<?php $user = JFactory::getUser(); if($user->id != 0) {    ?>
<?php echo $this->comments->form;?>
<?php } ?>