If your MW vents on the side then you do have to worry about side clearances. You shouldn't just jam it in between two verticles. The manual should specify what you need. I'd also spend a few minutes researching widths and clearance requirements for current models. MWs don't last forever and it would be a shame if yours died and you couldn't find a suitable replacement to fit your space. Ditto writerblock re the OTR venting issues you've read about. Two different subjects.

Yay! Finally! I moved into a home with a Maytag fridge and can’t remove the shelves for cleaning. It has the blue tabs. They must have been there for 20 years- I guess the previous owners didn’t know what to do either. Thank you Barbara Mackie!!

I think I would take three of the large pieces you have hanging on the wall with the windows and hang them over the shelves. Hopefully you have space for the other two somewhere else in the room. Then move the cabinet to the middle of the wall. I would not put anything on the shelves. A rug will interfere with the movement of the office chairs. A day bed with a trundle might work. You have to measure the room. Good luck.

I have something like this that folds and fits perfectly under the sink. I'm 5'4", and this allows me to reach the top shelves (my uppers go to the 8' ceiling).