There's not much difference between a throttle and a sufficiently powerful pedal-assist. Switch to your top gear, and the torque-sensor will say "gee that's a steep hill, let me give you a boost" the moment you start pedalling.
Banning throttles just makes manufacturers install token pedals on the motorbikes.
In theory maybe, but in reality pedal assist bikes are far more likely to be compliant with speed and power restrictions and designed to feel like a bike. While throttle bikes are almost always sold as dirt bikes for use on private property.