Then this line:
> if the president lets go of Taiwan, the CCP would be overthrown tomorrow.
doesn't make much sense to me. Who would overthrow the CCP, if not the Chinese people? And if they would be willing to do that, why wouldn't they believe in achieving reunification by force?
Letting go of the reunification aspiration entirely, and letting Taiwan relinquish their identity as Chinese, is a whole different matter and would make lots of people angry. It would be seen as a sign of a weak government, one which is in collusion with foreign forces to destroy Chinese sovereignty; an extension of early 20th century efforts by the west to balkanize China. The CCP will lose legitimacy.
Once CCP is overthrown, who can say whether the new policy is peaceful? Maybe a populist will make use of the anger to incite people to call for an invasion.
The CCP are actually moderates. Be careful of what you wish for.
There are different types of "Chinese", and as the PRC frequently does, you are blurring the difference between them.
Taiwanese are 中文 but not 中國.
> being Chinese is being 中国人, which doesn't mean belonging to the Chinese state
I wish that were the case, but the CCP declare themselves the arbiter and they have all the guns. People's Daily says we are "race" traitors if we don't obey their government.
So we don't like calling ourselves 中國人 anymore. I can read OK but not speak their 國語 well enough with the Taiwanese I meet to understand what they prefer. It is not a simple question. 或者华人? Maybe they ignore the pinks and still say 中國人.
我叫自己唐人
If the PRC were as reasonable as the relative you quoted above, none of this would matter. But they are not.
Hence, I did not say people believe reunification needs to be achieved by force. What I did say is that if foreign forces pressure China into letting Taiwan go, then China will fight back.