Whilst trying to create a role whereby tutors (TA) could grade, but not access quizzes (this might not be possible regardless), I noted that removing the three permissions to add, delete and edit quizzes has no apparent effect on the new role's capabilities.
1. Create new role, based on TA
2. Remove Manage Assignment and Quizzes permissions
3. Assign user to new role
4. Try to duplicate, create, edit or delete a quiz.
What I found, is that the new role can do all of the above. If that is the case for everyone, what exactly is the purpose of these permissions
Cheers!
Adam