If there was one thing that I might want to modify on the photo booth it would be the background or rim light. I would like to get some strip lights with egg crate grids and place them on either side of the background facing them towards the subjects at a 45 degree angle or less. This would help separate the subjects from the background better, giving them a nice edge of light around them. I don't want to change from the black background, which looks sweet!
See - Photo booth