Is there something specific that caused this halt on Cruise's testing permits?
If that car gets found doing something obviously illegal (speeding, running a red light, some kind of "reckless driving" camera review, etc) the registered owner is automatically assigned blame. They can potentially file paperwork to the court to prove someone else was driving (a lease arrangement, some valet ticket along with some proof from the restaurant or whatever at the time, a sworn statement from another individual confessing to it, etc). But ultimately by default the owner of the car is responsible for the safe handling of the vehicle. If you're worried someone is going to break the law with your car, don't give them your keys. If you don't like this, find another form of transportation.
Tag enforcement needs to be stronger. If an automated system sees a tag that doesn't make sense, it should be immediately flagged and enforcement dispatched. Lots of cops already have ALPRs, those should immediately trigger. I see so many cars out there with sketchy paper tags, this whole thing needs to be shut down.
Driving a car on public streets shouldn't be nearly as easy as it is in the US. Far too many people don't treat driving with the respect it needs.
10000% we need safer designs for streets and roads, better education, automated enforcement of speed limits, dis-incentives for larger/heavier/more dangerous vehicles, ...
All of these things need to be done, and can be done with existing technology today. We don't need self-driving cars to address our problems; they're essentially a distraction and an excuse to postpone improvements.