I have a twofold request here:
1. We should have the option to remove a background image from a project after we upload one. I uploaded an image that didn't work well but I had no way of reverting to the default background.
2. I would like the option to configure how background images appear. In my case, I wanted my background image to tile, but instead it stretched across the entire screen. (The most flexible way to handle that would be custom CSS for the project page, but I realize that could be...heavily abused.)