Re the chip manufacturing - would China have the TSMC plant on their list of things to bomb - or would the thinking be 'we own it now, don't break it'.

Excellent question. I guess it would somewhat depend on to what extent they had prepared facilities in China to take over production, at least for their own chip security.

If they had already prepared to take up the slack, then destroying TSMC facilities would only boost their payoff. They would be weakening their adversaries while capturing some of the global market for chips.