I think you will have to solve this manually.
If I wanted to reset all my board permissions, I would do this (as a founder Administrator):
Manage groups - remove all users from all groups except "registered user" (may be you want to keep the groups, than ignore this)
Remove all personal permissions (user names shown in the left side of manage windows)
Open all groups roles - set "all to NO" - save.
Open all forum roles - set "all to NO" - save.
Open all roles again - re-configure the settings
Check admin users and moderator users: which roles are assigned for user role, moderator role, admin role? -> reconfig, or regroup. You often don't need to assign a user role specific to user names - work with your groups and assign the roles to the groups! Than you can simply move users to groups.
Webseite, Blog, Wiki
Deutsche Übersetzungen - german language files
My 2 cents: Whether an extension is in the CDB says nothing about its quality. It is more important to read the support topics for it. Better to avoid authors who do not answer support questions themselves, who do not update their stuff, and who do not fix bugs for years.