when attaching the handles to the sides, sew the entire top leaving your 'to turn' opening on the side of the lining. This way you have a very secure top and a secure bottom of the bag. Your opening will be on the least stressed section (the side part of the lining). I am a bit confused by your picture. I never include the straps in the zipper. I think it would be to much stress on the zipper area. I put them on the side pointed down, stitch and then fold back to the top and stitch an x pattern. This is usually about an inch or two below the top of the bag opening. This allows for a lot less bulk at zipper and more ease in opening the bag.