Classes (group of Courses)

Content

I'm trying to determine the best way to incorporate a group of courses into our LearnCenter...  I'm interested in adding them as a "Class" and would also like to have them as individual courses should users who were not assigned this class would have access to them.  Is this possible?

Also, is it possible to add additional courses into an existing class?

The answers to these questions will determine whether or not I add these courses as a "Class," which would be optimal when adding it to a Learning Plan, or adding them as individual courses.

Is it true that if someone has previously completed a course that is a part of a class, that it will not reflect Completed for this particular course within the class?