Great tree skirt! It looks like you have already SITD around the outer twists? I notice a few wrinkles and I think you may have trouble doing any straight line quilting without puckers. Just my opinion and you can proceed if that is what you want to do.
Have you consider doing bar tacks or tieing in the open areas? If you spaced the ties at the same distance as your crosshatching it would bring it all together and prevent any problems with further stitching.