Hi Claire,
The easiest way to view all courses is to make a site-wide role. Be sure to close the eye when creating a site-wide role. Otherwise, every teacher will be asking who is Such-and-Such is and why is she in my class?
Site admin > Users > Permissions > Assign System Roles
But, be careful what your role wishes for. If you can see all courses, you can probably get email from all courses.