Most ebikes can handle up to 250 lbs., some go up to 300.
Riding on the sidewalk is not such a good idea because there are young kids riding their trikes and pedal cars, women with strollers and people walking. That's just inviting an accident.
For the motorists who are haters, bicycling has seen a resurgence in the last several years, so they will have to deal with it. Many municipalities have created bike lanes and wider shoulders for bikers. As a bike rider, you have to be careful how you ride and follow the rules...keep right, move to the center to turn left, use hand signals, etc. Distracted driving is probably the biggest reason people hit bikers. I always wear a helmet to help protect my cruller, but if you are hit you will most likely get hurt, maybe seriously.
E-bike rider weight limits are a suggested value and are all over the board, some as low as 200 and some much much higher to over 400 pounds, it all depends on how much you wish to spend. The rating is usually based on how long the battery will last and not the frame or components of the e-bike.
Helmets are optional for adults on any bike or trike in most areas except for sanctioned races. Do they work? Maybe. I've been hit by vehicles, both sideswiped and t-boned, on DF bikes and a helmet didn't help any. The sideswipe hurt the most as I ripped the right side view mirror off a Camaro or Firebird when it struck my upper thigh. The vehicle never slowed and I ended in the ditch. My custom hand built Italian race bike with full Campy went under the rear wheels of the car. That was in the late '70's training for a race in Georgia.
Anyone that uses a cell phone while driving should have their license removed permanently. Driving a motor vehicle demands constant attention. I have two signs mounted in my truck, one says to turn your cell phone OFF and the other says that seatbelts are to be used at all times. Truck doesn't go anywhere if both conditions are not met.
While your rules for bike riders are somewhat commonsense, almost no one in any city follows those rules. The motor vehicles don't follow many of the laws and regulations set for them, so why have bike riders follow someone's rules? It confuses everyone. You have just as much right to be on the road as a motor vehicle. Yes, we also pay taxes.