See we have lots of OMG alarmists here. It is no big deal.
Think about it, engines can say - run out of gas. What happens then? Well - you slow down and stop, all without the world ending (unlike! the! thoughts! of! the! first! poster!) Amazing the manufacturers thought about that possibility eh?
Transmission: Automatic, semi-manual, or stick manual?
Stick - no problem at all.
For the other two - if won’t harm anything if you just turn it off and not back on.
Steering wheel lock:
Q: Is there another position until it locks? If so, again no problem.
You should have 1-2 pumps of vacuum assisted brakes (you always have brakes - just have to push harder). Maybe more if the throttle body closes (DBW) or you keep your foot off the gas peddle.
Electric or hydraulic assist - yes that will go away (no big deal on a straight road). You can still turn, just more work.
No problem. The engine moving without being “on” is a normal state that happens every time you let off the gas with the gear engaged (no fuel is injected).
Self experience - I’ve done this countless times while tuning the car with the laptop. If you push the parameters just a little too far, you go into limp mode (very limited power). The only way to clear it is to turn the engine off and back on.
No big deal - on a manual where the steering does not lock. Just turn it off, wait a second, and turn the ignition back on (not to start). The engine is already turning, it just fires up and goes on…
I also routinely coast about 75 feet into my parking spot at work with the engine off. Guess that’s my part on being green.