You really failed to address some of my points, and misconstrued others. (Also, maybe cool it with the ad hominem attacks?)

We can agree to disagree about whether Taiwan is really the top priority for the Chinese government. You missed the key point of the hypothetical I brought up: I made it improbable precisely to point out that geopolitical situations change in unpredictable ways. What's the minimum timeline for reunification? 30 years at least? That's more than enough time for every significant relationship in the region to change. Are you really sure that through all that change, reunification with Taiwan remains the one constant need of Beijing?

The tunnel vision also applies to you missing the second thing I was hinting at: Taiwan does not need to be reunified with China to prevent the island from being "hostile." You seem to imply that Taiwan is hostile now, but Taiwan is a huge economic partner of China. There are many forms of military alliances and agreements other than annexation which could achieve the same goal. If you have doubts about that, look to the other global hegemon: the US gave up formal control of both West Germany and the Philippines without sacrificing its geopolitical interests in the areas.

Finally, you really missed the Okinawa point. You even brought up de jure sovereignty, after explicitly saying that political systems don't matter in the question! We can disagree about the Taiwan Relations Act, but the point is that your argument would be total nonsense if not for China's legal pretense for claiming Taiwan. If an island of Vietnam, the Philippines, or Japan was absolutely vital to Chinese military security, would you be making a claim that, no matter how long it takes, China would never rest until it claimed that Island? Even a political realist strategy would focus on building diplomatic relations without formal annexation.

You just have to accept, China's geopolitical interest in Taiwan is objectively well-founded and strong, but China's continued claim that Taiwan is a part of China is a temporary expedient for dealing with separatists in other regions as well as an ideological, not practical obsession. It is certainly open to change with time.