I believe that self driving cars will primarily be owned by companies with fleets of them, rather than individual ownership we have today. It doesn't make sense to have them sitting idle 23 hours a day. The owner companies will have a very strong incentive for safety since even rumours would be bad for business. They will also be in a better position to do something about it due to having multiple vehicles.

Well, I agree. That's why I expect that, along human drivers, the very concept of car ownership will disappear. It's much more efficient to have those cars available on call; they can serve someone else while you're not using them, and they can be parked&recharged at night with much better space-efficiency than cars are parked today.

Not if you're in a highway.

A plane can't just let go of all control surfaces. Heck it can't even leave them where they are. It must do something and always must provide some degree of control. A flying plane is moving at several hundred miles an hour and cannot stop.