It sounds like you're describing a 2-stroke engine, which older Vespas did use. But modern ones use a 4-stroke engine and should have the same emissions profile as any other motorcycle.
the elettrica motors are (obviously) electric, too, and for some models come in a couple versions.
Yes, but still terrible, pollution wise.
Electric Vespa anyone?
I live next to a road and combustion-engine mopeds vary from "holy fuck this is loud" to "I can't wait to move out". I used to live close to an airport and that was much better. The specific noise that mopeds make drills into your head. Funnily, I'm never bothered by nails on chalkboard or cutlery on plate, but mopeds, holy fuck, if hell exists, it's full of mopeds.