There is not that much sightseeing in Shanghai. There are many nearby destinations that offer more opportunities for sightseeing.
If you look at threads regarding delays, you will find that delays from/to Shanghai are usually significant and can be daunting. Not worth the risk.

The Earlybird fares out of AMS are very attractive. But most discounted Business fares from Europe allow one stopover in HKG. I wonder if there exists a slightly more expensive fare which allows a stopover. In that case, I would still rule out Shanghai and prefer TPE.
The first option you suggest would work out easily to TPE. TPE-HKG is a short flight with many daily flights. In TPE the museum is amazing, nice night market, nice spring resort in Beitou which is on the red subway line.
Option 2 is not feasible.