I like your quilting idea. Maybe stipple in the small diamond centers. If you do this with machine quilting, you might want to figure out a 'travel' stitch pattern to get from one center to the next. It's a pain to have to tie off each separated area, but it will make the outer squares puff up. Then I guess I would do a larger meander patttern in the areas around the bigger diamonds. Just re-read this, sounds clear as mud! Pretty quilt!