Excellent post but once China subsumes Taiwan - and that day is coming - they'll have TSMC's technology and that much more electronics production monopolistic leverage.
China won't be subsuming Taiwan anytime soon. If China did subsume Taiwan, TSMC would lose some of their process engineers, and this is apt to have disastrous consequences for their sub-14nm nodes as they are so finicky to get & keep working reliably.
The population replacement in Hongkong that's at its another height, will inevitably occur in Taiwan if that starts to be a remote reality, albeit at an even larger scale.
China doesn't have exclusive control of the borders with Taiwan, for population replacement (or just flooding Taiwan with loyal Chinese citizens to alter the demographics) it would require the Taiwanese government to look the other way, or encourage it. Neither is likely to happen, as their government isn't asleep at the helm.