Found an ignition kill fuse... is it good?
 

On a 1996 Subaru, Fuse 16 powers the fuel pump relay and ignition coil. When I pull it, the engine dies, but my instrumentation and illumination keep running. When I reinstall the fuse, the engine is ready to start right back up. That seems like a good spot to put an ignition kill relay. My biggest concern here is that the fuel injectors would continue to operate while the engine spins down. My second biggest concern is that I'll be cycling the fuel pump on and off thousands of times.

Is an ignition coil + fuel pump kill bad for the car at all?

Maybe I could kill the fuel injectors: There is a spot on this wiring diagram where I could kill all four injectors with a single switch. See the 12V rail: YEL--))--YEL/BLU between the fuel injectors and the main relay, left of the MAF. However, even if this is a single, physical wire, I doubt I'll be able to find it. Also, my engine compartment looks like it's been through a salt bath, with 13 winters of Buffalo road salt so far. I'd prefer not to mess with any wiring under the hood.