I like the ideas previously expressed, especially the one you have about enhancing the star! I, too, would leave the scroll work around the pictures as they are. As to the center panel, I would probably simply do stitch in the ditch so that the quilting does not detract from all else going on. The border--depends on how wide it is. Does it really need quilting? Perhaps just something simple so that it doesn't detract from the beautiful blocks. Maybe something as easy as straight line stitching and inch or so from the edges of the border fabric. What kind of frame would you use, if it were being put into a traditional picture frame?