Very cool quilt! Echoing the star would make a big impact. For more impact, but still pretty easy without rulers would be to do your echoes so that some were closer together and some further apart, you could then add some fills such as string of pearls in the channels that are further apart. My only concern with echoing the star completely to the edges is that you would need to make sure you did something inside the star so your quilting is equally dense in that area, otherwise you could get a wavy quilt. You could ditch quilt all the pieced parts of the star that are done with patterned/colored fabrics and then do some interior echoes inside the gray solid star, that would help to make the quilting equally dense throughout the quilt.
Another possibility would be to use your walking foot and do some diagonal lines from one corner to the next skipping the solid star and the patterned part. Then you could go back and ditch the patterned part and echo inside the solid part. It would end up looking like your diagonal lines go under the two stars. To get this effect looking right you would need to mark start and stop points on either side of the star(s) so they line up. You could do this with gentle curves for w wavy effect also.
Lots of great possibilities here.
Rob