Leaving airport to sightsee during a 23 hr layover when having a following 2 hr. layover in Shanghai

You need to get visas before departure. More than 1 landing means 24 hours total including in air time.

To add, even if you don't leave the airport you will also need this visa in advance or will not be allowed to board the flight in Thailand.

The China Eastern Customer Representive (CR) confirmed what you (CDKING) said: I will not be able to board the plane in Bangkok without a tourist visa, given I will be in mainland more than 24 hours in 2 different locations. A Chinese worker at the Chinese Embassy Songkhla, Thailand said the same thing. But, personnel at the Chinese Embassy in Phuket, Thailand told my Singaporean friend (who called on my behalf and talked to them in Chinese), after hearing the entire scenario (including what the Chine Eastern CR lady and the Songkhla Embassy lady said), that as long as we stay in the airport in the transit (secure) area, there is no need to obtain a visa, even if our total transit is more than 24 hours. She said we would have to confirm with CE airline that we will not leave the transit area in the airport. Does this sound right to you, especially if we arrive in Chengdu in Terminal 1 and depart from Terminal 2 (as indicated on my e-tickets)? This would assume that you can travel from Terminal 1 to Terminal 2 while staying within the secure transit area for international travel. I am not sure about this either.

And, if we can do this, is there a lounge in the secure, international transit area that we could stay in with children under 18 years old, even if we have to pay for it, in either one of these two terminals in CTU?

Embassy is wrong. Airline will handle it properly and you wont be able to fly.

They are misinterpreting this part of his part of TIMATIC:

"Passengers with a confirmed onward ticket for a flight to a third country within 24 hours. They must stay in the international transit area of the airport and have documents required for the next destination."

Your flight to the third country (departing Shanghai) is in over 24 hours. Also Chengdu to Shanghai is a domestic flight thus you will be leaving the international terminal transit area. T1 to T2 is landslide and not the secure transit area. Its similar to the USA where there is no airside international to international transit.

Okay . . . that makes a lot of sense of all these conversations--especially the change from international to domestic terminals. It is totally not worth risking it! I am going to call my credit card booking reservation CR to look into changing my tickets to see if that is less expensive than jumping on a plane to Bangkok this Monday, requesting tourist visas from the Chinese Embassy for each of my family members, and waiting at least 4 days to pick them up. Otherwise, I guess I will have no choice but to do exactly that! Thanks; you have been a great help! :-)