What are the must-do activities when visiting Shanghai, China?

After much deliberation, I have finally booked my tickets. It will be in December.
This is a family trip with my children.
It is a 3-day, 2-night independent trip.
I have already booked a hotel for 2 nights within walking distance (400m) of the Bund.
I am planning a basic itinerary including:
Taking a city tour bus.
Visiting the Oriental Pearl Tower (I want to go up).
Visiting the Provisional Government of the Republic of Korea.
Visiting the Bund.
I am thinking of this as the basic schedule, but
are there any "+alpha" recommendations?
Since I am now in the selection phase, I would love to hear the intuition of those who have been there regarding what to add or remove.
Because the itinerary is short, I can't visit everything, so I need to make choices.
Nanjing East Road, Yu Garden, Wukang Road,
Xintiandi, Tianzifang, Shanghai Museum, Water Towns, etc.
Since I can't do it all, which few would be the most meaningful to include?
Instead of just recommendations, please also tell me "that place is mediocre" so I can skip it. lol