I love the choice of backing! It really looks like a playing card. I hope you figure out your quilting, this quilt is so special I am sure there will be lots of opportunity for it to win in the show. Can you consult with a local quilter to have her give you ideas for the different areas?
I tend to stabilize the areas and then embellish as I go along letting the quilt "tell" me what would look good there. Like the laces could have some defining lines, the hair could have lines to make it stand out. But, you idea of the all over quilting could be the best choice since cards are a flat object normally. Oh, I can see why you are torn between quilting ideas. I am sorry I am no help. I do love your work though. This is amazing.