I agree.
In my various conversations on this topic around the bay area, people are generally overly optimistic, who believe it'll happen in next couple or so years, and people who are overly pessimistic.
Possibly a gross generalization but generally the people who are overly pessimistic are the ones who are or have till recently been engineers, while the people who are overly optimistic are the ones further away from engineering - with the farther they are the more optimistic they are.
Moreover, in addition to what you wrote there are a lot of other open questions, not necessarily in any order and definitely not a complete list:
1) Auto Insurance (cars below refers to fully autonomous cars):
1.1) What happens to auto insurance? Do I still need to buy it if I'm not driving it, or does it come bundled in the car price?
1.2) Does everyone pay the same auto insurance for the same car model/year.
1.3) Do cars with different autonomous models have different auto insurance?
1.4) What happens in the case of car accident between self-driving and non-self driving car?
1.5) What happens in the case of two self-driving cars' accident
1.6) What happens if a person is killed due to the Car's fault. Who is liable? The insurance company? The Car manufacturer? The self-driving module manufacturer?
2) Some Edge cases
2.1) What happens if on a 4-way stop 4 self-driving cars come to stop at the same time? Do they know how to handle that, as in which car is moving forward and which one is allowing other cars?
2.2) What happens in an emergency? Can I force my car to drive rash to the hospital or will it follow the speed limit to the T.
2.3) What happens if the Car runs into a situation which it is not trained for?
3) How are the cars tested?
3.1) As a consumer do we know that the cars are fully tested to handle ALL edge conditions?
3.1.1) What is the definition/definitive list of ALL edge conditions?
3.2) When will we know that the threshold has been passed, and the car is truly autonomous?
4) Security
4.1) Assuming the cars will need to be connected, how will the security be?
4.2) Can the cars be Pwned? I'm sure they can be.... so this is the rhetorical question
4.2.2) If the cars can be pwned, will the fully autonomous cars become the next WMD (Weapon of Mass Destruction) -- if you don't agree, close your eyes and imagine a fleet of hundreds of thousands or millions of fully autonomous cars under the control of a rogue entity hell bent on causing damage/killing people.
4.2.3) How do we protect against that?