For the white background, you need to importe the files again using the editor.
Argh... wait a second before you update. I'm a little unsatisfied with how some pictures went.
..I'm not sure, I just use photoshop's magic eraser. I had paint.net once too.. but I never really used it much.
Question about this transparency thing: so when you guys edit the images to get them translated, they lose their transparency? How is that possible?