Gorgeous!
I'm no expert, but I remember someone doing straight lines from a star to the edge of the top and it looked like "rays" from the star. Maybe use a shiny black thread, like embroidery thread, and just continue the "stitch in the ditch" but from the edge of the star, change to black. That way, when people look at it from the back, the lines would start in the center and radiate out to the edge. Just my two cents worth!
Please post a picture when you have it quilted, would love to see what you decided - I'm sure, no matter what you decide, it will be beautiful.
Good idea on appliqueing the star to the background!