Someone has to die, preferably several, before the politicians do anything. They'll start with a ten year study.It will be interesting to see how injuries in those circumstance play out. If you were riding a bicycle, your home insurance liability coverage should cover you. If you are riding an unlicensed motor vehicle, I expect insurance will tell you you're on your own. Expensive lesson in being an ass.
How about the last registered owner gets the judgement in the case of damages or injuries? That could be the owner of the shop that sold the thing.
Two simple steps to build upon would be an operators card similar to the boating one. The boating one has little to do with actual techniques but rather marine laws. A person can't plead ignorance. Same with e-anythings.
Secondly a permanent licence plate should be required.
If the politicians think the liabilities are negligible let them sell insurance for $50 a year and make a killing.
P.S. If the eco warriors are so adamant about saving the planet why aren't they pushing pedal bikes. Zero emissions, 90% recyclable, obesity fighting. Most E things are toys for lazy people.