My only experience with scooters are the two I mentioned, although I have read about many, it is mainly brands you should limit yourself to.
Within those brands there maybe models to stay away from but you would have to ask for specific models you can find or willing to drive and purchase. I would not be able to put together a list of models, you listing as you did is a better way.
Used or New
Depends on your budget.
I have never had anything new, on used you do need to know something about what you are looking at for the most part or purchased from a dealer that will give some warranty with your purchase. Buying used from a dealer does not mean the scooter will be right, that depends on the dealer.
My most recent purchase a few weeks back was a 2010 People S 250 with 200-300 miles on it and looks, runs and performs as good as the mileage shows. My vintage scooter had 17,000 miles and needed some work.
If you get a used scooter with miles on it, maintenance items might need service, Rollers, Belts, Tires, Brakes, etc.
If I am a dealer I would not take a photo of a bike that was not prepped and ready to sell as in the HD200.