Neat idea. But it really isn't all that much better than a hidden kill switch. If you find it, you can still bypass it. And if they never start the car (and the professionals aren't starting them most of the time), then it isn't an issue.
Same thing with the steering wheel. Yeah, you need it to drive away. But if you're not driving it, it's not an issue.
A cheapo hidden micro switch will defeat the guys that need to start the car. A back up fuel kill will defeat the smarter guys that still need it to run. And if they don't need to start the car, you probably won't stop them. Think repo-men and tow truck drivers. They don't need the keys, they don't need it to run, and in a lot of cases, they don't even need it to roll.