I think your quilting pattern ideas would work. I'm afraid the red/white/blue variegated serger thread will not look that great though. I would suggest a Glisten metallic thread from the company that makes Glide thread:
http://www.bobbincentral.com/quiltin...d/glisten.html
I am thinking one of their silver or gold threads would look really nice with everything. Metallic threads can be a pain to quilt with, but Glisten is supposed to be easier to handle than others. I have had really good luck with their Glide thread, and that could be an option for you too, but I think a metallic would really make the quilt sparkle. (There is a little sparkle in Glide thread also that makes a quilt shine, but I assume the metallic would be even better.)