Hello @rtoon
I was able to look into this question. I was curious about this, myself.
In my testing, I was surprised to find out that the admin role has the ability to edit New Quizzes from the build screen no matter what permissions are in place...I also created an account role with the specific permissions you listed and was seeing the same thing.
It seems that has been an ongoing conversation taking place in the community over the last couple years. THIS feature request (not totally related to your post) was added to the community and discusses a possible New Quizzes Permission Set that could be configured for account roles.