“placement” — I’m not an authority here, but tend to agree with FUTR that the weight of the door is a major consideration … again, the instructions on the safety card will have words and pictures describing how to open and remove the door, and where to put it

“mechanics” — I believe the overwing exit doors on many newer models are hinged at the top … they rotate outward and upward more than 90 degrees, so where to put the doors isn’t an issue