Replaced NSS switch/wiring.ballest resister.voltage regulater.alternator now what???

A burned/meted spot is a little different but these cable housings are pretty durable so it shouldn't be a big problem unless it's melted all the way through. Eventually you'll want to replace it but not immediately and no local parts store will be able to get it for you but there are several sources online.

The "wire" inside is the cable, the housing is around it so yes, spin the wire inside.