No idea on you shifter. But a protip, it only costs like 20 dollars to rent the homedepot truck. I can't think of a part that costs less than 20 dollars on the car if it were to get damaged. Next time, rent a truck.
There are two kinds of pzeros that are on the 2015 mustang. If you have the performance pack, you get summer only p-zeros. If you don't then you have p-zero nero all seasons, which is what the OP is shit talking. The PP p-zero's aren't horrible, though they are not the very best tire.
This looks like the seatbelt was rubbing on the strap and not some guy's tool. I've seen another thread on mustangforums.com, don't have a link handy. I would make sure you keep the twist in the belt before the strap.
The clips on the passenger side were broken when I bought the car. Only noticed it during the summer when the heat started to warp the fender under the head light and took it to the dealer.