Help for creating an all-in-one education resource.

I am creating a al-in-one education resource for educators. It will allow teachers to communicate with educators of other schools, but at the same time manage classes, add grades, etc. I am currently using buddypress for the social part, and sensei for the courses. I have a few dilemmas and questions I would like to ask.

1: Is there anyway a user who registers as wordpress user, can use that same account with the sensei plugin? (for students)

2: Is there a plugin that allows educators to create and manage classrooms.

3: I need a good gradebook plugin so each teacher can have their own gradebook.

THANK YOU SO MUCH!