Usually the reason that a professor has strict rules is because of previous students.
Don’t be late because it disrupts the learning of other students.
Don’t go to the bathroom because the in and out disrupts other students (or could be a method of cheating during a test).
Your professor has a goal for the class for what you are to learn. He feels that 4 page essays are what you need to do that. If you are having issues, go to the Writing Center or see your professor during office hours.