Thanks Howard, yes am trying to avoid full blown multi-tenancy. If I could set the 'institution' as a cohort and limit a user to manage that single cohort only, this could work. But the user should only be able to see and add/remove from that particular cohort. I've seen some questions on creating a 'cohort manager' role but no replies.
You can organise your Institutions as Course Categories and then assign Managers to individual Course Categories. It gets you some of the way there.
Thank you very much, have played around with a combination of cohorts and course categories and ticks most of the boxes. Appreciated!