Where should I tap in to wire a kill switch? The only thing I want is for the car to not start unless the switch says otherwise.

 

The Easiest is to wire it, to Disable the Ignition System, and also so it Can't be Hot Wired either!
You're going to have to do some research to find the Best place for that,
or buy a decent Remote Vehicle Disabler, and then it Can't be Started, until You give it the Command!!

 

Fuse #14 simply just says ignition system, should I tap into that with a fuse holder that has an inline switch? Or should I instead tap into the fuel pump relay and put a switch there? I don't know where the fuel pump relay is.

 

At the risk of owning it, I'd use a fuse buddy with some skill and use it to turn power to that fuel pump fuse on/off.

 

OP - I know thieves expect cars to run and most are not up for troubleshooting while stealing but I suggest you not leave an obvious clue with wires hanging out of the 'fuel pump' or 'ignition' circuits. I mean, if they clone your fob, that gives them time to look if you know what I mean. Also, I would want something more sophisticated that at least latches the horn on, so you know there was an attempt, otherwise you never know anything happened.

 

To keep it simple in my example I'd add a switch to one of the poverty button locations =)

 

What would you recommend I tap into? I'm thinking I tap into the fuel pump relay in the engine bay and run the switch somewhere into the cabin. It atleast more hidden than just tapping into the ignition fuse in the cabin of the vehicle.

 

I was thinking I would hide the switch instead of just leaving it out in the open. The best scenario is I have 2 switches setup, one to kill the fuel pump, and one for the ignition system. It would still be more protection over the average single switch.