Some thoughts:

1)Helmet laws:

I've always found helmet requirements pretty arbitrary: if runners who run at 10-15mph aren't required to wear helmets, why force them onto cyclists and scooter users?

Such laws have been known to adversely affect ridership, which, in turn, decreases safety for everyone because drivers don't expect cyclists/scooter users. I've seen a study that found that the net effect is that helmet laws decrease safety.

2)No sidewalk riding:

Good. I'd argue that even if bicycles could be OK on sidewalks, e-scooters/e-bikes should not be, because there's no incentive for e-vehicles to go slowly on sidewalks.

For cyclists, intermittent slowdowns enforce a low speed, because it takes effort to accelerate. But on an e-scooter, all it takes is a turn of a handle to get to 15mph in a very short span of time.

So, while there's a physical cost for cyclists going too fast, there isn't one for e-scooter users.