E-Brake Shoe Busted, Does Backing Plate Need To Be Replaced?

Long-story-short, I was hearing some bad rattling and grinding from the back left and it was most definitely the e-brake shoe on the left rear wheel. I removed the wheel and the brake caliper and the broken pieces came falling out... The ABS sensor appears to be broken, the ABS wheel also appears to be pretty ground down on the teeth (see pictures). The other issue is that the two top bolts securing the backing plate have been sheared off (see picture) and the body of the bolts were left inside.

My questions are :
Do I need to replace the ABS rotor?
What is the best way to fix the backing plate situation? A new backing plate, just new bolts or just spot weld the plate in place?

Thanks again for the help!