First of all, I want to congratulate you for the excellent work with WPdiscuz.
Wel... I use my blog configured without Gravatar. And when I installed WPdicuz 7 beta 8, the left padding of the comment form is showing up with an error.
I don't want to make the rich editor available to guests or other users.
In my experience in making the rich editor available in Wordpress's standard comment system (this for example https://wordpress.org/plugins/tinymce-comment-field/ ), most users don't know how to use it and that even disturbs them.