That window is killing me. Both me and my wife hate it for different reasons. We would just remove it if we could but code won't allow us to.
The drapes sound like a good idea or we might just place a sheet of plywood in it and make it flush with the wall on both sides. Then I can put the absorber on top of it. If we put drapes on one side and an absorber on the other would that have a negative effect?
Putting the desk on casters is a good idea too.
How important is it to put traps in the wall-ceiling corners and are these small boxes like 1' x 1.5' or do they have to be around 2' x 4'?