Looking at the pictures of your room, mounting the side surrounds above the window and closet seems a great idea. They don't have to line up with the window or closet exactly, as they will be above them, matching the rears in elevation.
Moving the couch forward will improve the ambiance from the rear surrounds, and I think you will notice a significant improvement in the sound field.
To test it, enlist two friends to hold the speakers in place whie you play a 7.1 scene. Barring that, put a nail or screw in the wall, and use a piece of wire hanger to temporarily mount each speaker.
"The wise understand by themselves; fools follow the reports of others"-Tibetan Proverb
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.