Wouldnt running the alt cable to the batt. side of the ford start solenoid also work for keeping the alt cable from being hot after the kill switch it thrown? So using the same power cable from the batt to the solenoid as the recharging line.
You don't run the starter cable through the cut off switch when using a ford relay. The idea is for that cable to be hot only when starting the car. Run a separate cable to feed the car. The black wire going to the rear and back forward feeds the car. The black line has a 60 amp maxi fuse inline, going to the switch... in case the switch goes dead ground.