Answer A - The Cole Hersee switch should work. The problem will be pitting
of the points everytime you use it to turn the motor off. However, ignition
switches are designed to handle a certain amount of this.

Answer B - You do not need an additional fuse. The 15 amp protection at the
distribution panel is adequate to protect the 14 gauge wire. Using 10 gauge
wire for most of the run is a good idea, that will help minimize voltage
drop and keep the motor happy.

Rusty O