Wendy,
as for no. 2, China never pulled out of the 1976 Olympics (which would have been the one at issue) because they were never in, in the first place. Wikipedia is correct: China was not in the International Olympic Committee at the time, so they could not have participated in any case.
They were not in the UN until 1972, either.

The reason for this was the decade-long international quarrel, as part of the Cold War, over who was entitled to represent China in international organizations. Which is a far too complicated issue for a forum post, but this Wikipedia article gives a good summary.

There was actually a boycott of the 1976 Olympics, from several African nations over the South Africa issue.
But in short: the reference to China pulling out of the Olympics, is artistic licence.

Thanks so much for the response and information, TJ!