You are correct EastsideAl!

They removed the main floor seats during the nightclub era. I have the seating floor plan that shows the positioning of the tables and chairs during the early 70s nightclub era. It's almost too big to scan however. Maybe I'll photograph it and post it.

During that era the mezzanine and balcony were closed... but as you mentioned... wandering off into those areas was likely not that difficult.

The Michigan did poorly as a nightclub... partly because the food wasn't that good. One reason is that they didn't have a real kitchen in the former theatre space. I'm not sure what kind of make-shift catering operation they set up, but I'd be interested to find out!