>1 - bikes are already great, really cheap, and actually good for you to cycle. We also have an obesity problem in most western countries.Maybe this is another case where things are different in other countries, but: you still have to pedal on an ebike. It's not like a mini-moped where you just twist the throttle and the machine goes forward all by itself, with no work on your part. You have to put in some effort, and the electric motor multiplies that effort. And the motor cuts out above 15.5 mph so if you want to match 20mph traffic you have to make up that remaining 4.5mph by your muscles alone. In my unscientific judgement it feels more strenuous than a brisk walk, less strenuous than jogging.
In my experience, most of the benefit is actually at low speeds because of the better acceleration. After waiting at traffic lights I can clear the junction faster from a dead stop, even if I forgot to change gears.
So yeah over any particular distance it's less exercise than a normal bike. But in my experience it makes longer distance journeys feasible in the first place, particularly over hills. I use my ebike way more than I ever used a normal bike. It's kind of like that Jevon's Paradox[1] where energy-saving devices encourage people to use more electricity -- my effort-saving bike somehow makes me do more effort overall, from the greater mileage.
>2 - they let inexperienced riders go really fast on bikes that are 3 x heavier. You see so many idiots cycling though red lights at 15mph weaving in and out of pedestrians. If you want to go that speed on a regular bike you have to earn that speed by cycling for many years
I can't make broad-brush excuses for cyclists who jump red lights. In most cases it's obviously bad I don't know what the situation is like in your city. But in a few cases I think it's justifiable and I do it shamelessly at particular junctions. Traffic lights commonly detect cars by an induction coil embedded in the road surface. These devices are often not sensitive enough to detect bicycles. So you can end up in a situation where the light will stay red forever for you. In my view that makes the lights defective and it's justifiable to skip them (with extreme care ofc). There are other particular junctions in my city where I do it. These are ones with dedicated bike-triggered lights but they don't always work and have dumb timings, and the layout is peculiar so you can safely cross by hugging close to the pedestrian barriers through a red light on certain phases. It's always faster and just as safe.
And some junctions are deathtraps for cyclists whether they go at green or red. I avoid those like the plague.
If they are "weaving in and out of pedestrians" this may be a sign the city doesn't have adequate cyclist and pedestrian infrastructure. It is not difficult to design streets so that people walking aren't disturbed by bikes, in fact it's much easier than designing them so that people biking aren't disturbed by cars.
[1] https://en.wikipedia.org/wiki/Jevons_paradox