I ended up taking the zipper out, three layers of stitching, but worth it. I basted the zipper in by hand then used the double stitch on either side.
I’m quite happy with the results, the redo was worth it.
I’m going to tack the lining to the seam allowances after I receive and attach the hardware. The straps will be attached just below the zipper on either side of the bag. I’m using a stiff(ish) thin poly in between the outside fabric and lining to help the bag keep it’s shape but it’s still flexible. I found it in the home dec area of our local Fabricland and use it in my quilted baskets as well.