Just a thought, can the StudentCourse table be extended to include the InstructorId column, and then remove InstructorCourse table?

Since you have a SLA of 99.999, I assume you have a test/ R&D environment in parallel with the production environment. I agree to the proactive approach. Any required (=...

I feel an underscore (_) may be better in place of the (.) to avoid confusions 🙂

You need to create a user in the database, map it with the login created, and then provide appropriate permissions on the objects.