MN Bobber,
Well, the kill switch is for the ignition, so I don't understand your question about the headlight.
1. The kill switch is there in case the engine over revs and you cannot stop it with the throttle. That's why it is located where you can reach it without taking your hands off of the handle bars.
2. Also handy to shut off the engine just before you crash into whatever you are going to crash into so the engine isn't running when the bike lands on your legs.
3. Depending on how your bike is wired, the kill switch also allows you to run the starter motor without the ignition on so you can do a compression test.
4. The other purpose of the kill switch is to allow you to work on the electrical system without frying the coil and / or points.
5. I routinely use the kill switch to shut the engine down so I can find neutral before turning off the ignition switch.
6. You can use the kill switch to shut off the ignition when you kick start to prime the engine.
7. Removing the kill switch will also upset your insurance company because it is part of the bikes safety equipment. This won't matter if you get hit by a beer truck and it's not your fault, but if it is your fault, the insurance company may look at everything to get out of having to pay the liability, and altering the safety equipment of the bike may let them off the hook even though it had nothing to do with the accident.
