Why are the rear tires wearing on the inside? The outside tread rear looks new.

This means that your Rear Camber is to far in. The only reputable Tire chain that can align the rear Camber is Firestone. They have special U-shaped wedges that can make the tires ride more upright. Goodyear had this technology 20 or so years ago. I do not know if they have it now.

no, get the alignment in the rear corrected. it is out of alignment and needs to be adjusted. Roy