You have plenty of good ideas here. I'll just add my two cents. I always use blanket stitch around my appliques. You can do a couple of straight stitches first to secure it, then blanket stitch right over the top of the straight stitches. You won't see them. I've done this with satin stitch too, but I think blanket stitch ends up looking better, especially if you haven't done it a lot. You must stitch down all raw edges so they don't pull up. Then you can do your decorative top stitches. When that' all done, make the quilt sandwich and quilt away!