Which best watertown: Zhouzhuang- Nanxun - Wuzhen + travel to and from Shanghai

Hello,
I hope you can help me.
1/ I know that Zhouzhuang is the most commercial watertown but which of the three is more authentic and pretty, architecture and atmosphere wise?
2/ Also, if one has seen Suzhou, are these three towns the same thing?: if you've seen one, is it worth seeing another one?
3/If I am coming from Shanghai in the morning (by taxi? what would be the quickest option and how long would it take?) and want to leave to shanghai again in the evening, do I have enough time to visit one, or maybe even 2 of these towns?
4/ also, do yo know if the "soft sleeper" night boat ("Paradise Pleasure Boat" or another) between Suzhou to Hangzhou is still running and if yes, what are their timings in both directions please?
Thank you so much for your help!