Thanks for the pic. It looks like the shine on the leather handle has rubbed off a bit but nothing bad. That's pretty normal with use on any leather product that's not heavily coated. You say the leather has peeled off? If the outer layer is actually gone, which is unheard of on a DG piece, the LV will probably replace the bag.
It would be hard to prove the scratch on the pipping was a defect as these happen with use as well. The piping is there to protect the corners so it takes most of the beating on these bags.
The excess canvas... That's hard to assess from a picture.
If you are really concerned, you should take the bag back to your local boutique and ask the repair specialist to assess it directly. But honestly, from the pictures, I can't see anything that seems "obviously" defective.
Good luck and keep us updated!