You will be using Group forum permissions
Guests - Read only access role for Rules and How-to, No access for other forums
Registered users - Read only for stories and chapters
For Comments, something like this:
For
Authors, Full access role (+ polls, if desired)
Use this extension to automatically add Registered users to the Authors group after 25 comments (the only posts they can make) -
viewtopic.php?f=676&t=2555611
For Mentoring authors, add permission "Can post stickies". They will hve to do that - no way to automate all posts being sticky by group.
You will want to create roles for the permissions for these groups, except Guests and Authors (those roles already exist).