I copied your picture and opened it in paint ... now my drawing skills leave a LOT to be desired, but I figured it would make it easier for me to explain!
FMQ in each stripe I would do either a star or figure 8 or whatever you want ... in the same colour - so white on white, blue on blue ... or you could just do the white and skip the blue
For the borders - I've done this and it turns out really nicely - 1/2 inch straight lines all the way across each border overlapping at the corners ... gives it a really nice touch. Again, I would use the same colour as the fabric.
You don't want to take away from your quilt - which is gorgeous - so your quilting should be very simple.