SPIN Sprite Sheet Maker

[Mighty Jetters]

hate to bump but I wanted to ask about why when I load multiple images into the program (they're all 32 x 32), when it automatically compiles them into a sheet, it doesn't allow me to edit the spacing. the images all stay glued together. which is okay but I'd rather them be spaced out by 3 pixels each.
I also wanted to ask if it's possible to make it so that you can have the sheet background (or the spaces in between the graphics if you prefer) be a solid color, and the graphics appear as alpha transparent cutouts so that one could see more clearly what the dimensions of the graphics are.