Tim, a few of the switched points that could be picked up on would be heater blower motor, one side of gas guage, radio connection, an I think there are some on the headlight switch.
As far as the wire guage question, I can reason it both ways. I think the large wires on 6V is more to get maximum current for the starter. The formula is current (Amps) = Voltage divided by resistance of the circuit.
