Do I need to install a fuse on a altenator wire?

Keeps the exhaust from rattling on something.... like the driveshaft?

It's your car .... but um, electrical shorts have been known to burn down cars; too much protection is good protection.
IMO, spend a day or three and go thru the harness, especially the bulkhead connector and the headlamp switch, which is where the majority of issues are gonna be.