First off you really don't want anything else running when AH is open.
Granted there are guys who tab out to read the bbs while climbing their bombers to alt, etc. But as a general rule you want to run AH totally clean.
Second, you need every inch of visibility you can get. If I could afford a wall sized monitor you can bet I'd have one. So why would you want to size it down to a window? If you really need to hit the desktop, alt tab out and back.
Yes I cringe when software does things I don't want/expect it to do.
However in this case IMO your expectations are out of line. Full blown flight simulators shouldn't run in a window. And you shouldn't be trying to do anything else while running one.
Your wife may put on makeup in the car on the way to work in the morning. But you wouldn't expect her to do it if she was driving an indy car at top speed would you? There is a time & place for Multi tasking, but AH isn't it.