I'm not going to be of much help, but I do agree do NOT tie it. I think this is a lovely quilt and enjoy the variety of fabrics/prints. Maybe because it has a scrappy appearance, a kind of scrappy (lavender and other colors similar to the patches) 'coins or piano keys' or something would be nice in the outside border but use a thin dark inside border to break up the sqs from the scrappy outside border.
looking forward to reading what others suggest.