Is my room OK for Magneplanar 3.6's

your pushing it with the size of that room .Maggies need to breathe.Your room might work but again pushing..good luck

I have my Magnepan 3.6s in the end of a 11 ft wide room, with the speakers about 3 ft from the baack wall, and only about 20" edge from side walls, with the tweeter inside (rather than outside edge)
I sit about midway into the room so the speakers are 7 ft from me seated position. Great.
One thing you might also try with a square room is a diagonal setup, so the room is a diamond in relation to your speakers and your seat.

I agree with Schipo