I'm guessing that since the fuel pump's fuse is 15A, then I'm gona need a 15A relay right?

 

That’s what I did. Clutch cut kills the starter. Fuel pump prevents the car from being push started. And I added another line kill just to be sure my car doesn't go anywhere. (the person that buys my car is going to hate me)

yes that's right. But I'd go with the 30amp Radio Crap relay. their 15 amp relays are highly overrated. I've destroyed more than one with under 10amps running though it.

IMO it’s easier to just stop the OEM fuel pump relay from turning on. Interrupt the green/yellow wire running to the main relay, just left and behind the fuse box under the dash. It has max of 0.5 amps running through it.