Transit without a Visa through PVG?

Some quick answers...

1.  No. While there are exceptions, I would not suggest you press your luck. If you violate Chinese immigration, there would be serious consequences. You arrive in Shanghai and you stay at the airport. No one will let you leave, certainly customs won't. However, if you did manage to egress from the airport, you won't be allowed back in. Yikes!

2 No. If you want to visit China, then you need to apply for a visitor visa. If you want to work in China, then you apply for a working visa. If you want to marry a Chinese person, then you apply for a Chinese spousal visa. China is very cut and dry. It is straightforward. When you try to bend all the rules to same some money, squeeze some time, or make life convenient, then you risk serious consequences. When in China, follow the law.

3. No. All visas are given on an individual basis. If you have reason to be in China for ten years and can prove the need, they might grant it to you. Otherwise, you sure better provide details on how long you will stay, where you will stay, and which whom, and why. They will then craft your visa from that information.