Hi John

Thanks for the explanation.

I think using permissions to allow users to act as everyone's manager and assigning these by audience is a good option. There are a few hundred  permissions so fine control can be applied to the role.

There are permissions to  enrol user, manage user enrolments, unenrol users from the course , add attendees to seminar event, remove attendees from seminar event that should provide most of the functions required.

Regards