Let's talk about
2, on the idea of legitimacy. I'm very ambivalent on this front. CPC is chosen by the Chinese people, not through voting but through fighting, because this is the political entity that can provide a stable life to most Chinese. If you look at Chinese history, the destruction of each dynasty is caused directly by peasant/famer uprising since they can no longer live due to heavy taxes, wealth inequality, and natural disaster. People do care about national rejuvenation and all that big stuff, but what keeps you from protesting on the streets and overthrowing your government is whether you have a stable job that can feed your families' mouths. Ideology and pride cannot feed mouths. This is also why 1989 failed, because it was only the urban population protesting for ideological reasons, but the majority of the Chinese who are farmers, still supported the CPC since they are not starving and have roofs over their heads - or at least they did not care enough to rebel. My dad was in Shanghai where Jiang Ze Min was the mayor in 1989, they were on the streets protesting too and Jiang came over, gave a speech, and promised to have pork ribs for dinner in their universities, and everyone shut up and stayed off the streets lol.
Now is Taiwan issue an important one? Yes! But will being soft this time cause any turmoil within China? Unlikely for a couple of reasons. First because China's politics does not work through public awareness and protest, CPC pass policies based on what they think are ideal, not based on reactions from the people (many CPC policies are deeply unpopular among the Chinese but they still get passed) - going to the streets as a way to pressure the government is not exactly a Chinese way of doing things, this is why you rarely get peaceful protests in China, people either go batshit crazy or do nothing at all, I think its a cultural thing.. So I do not expect protests to emerge across China if China does soft this time around, things just don't work like that in China. What about legitimacy? I don't think that is a concern either. Chinese who like the CPC will like them regardless of what they do in this situation and justify their decisions, and Chinese who already dislike CPC will just find any reasons to bash CPC. Perhaps a few young people who held favorable attitudes to CPC over its perceived military strength may get disappointed if China does not act forcefully this time, but this will be quickly forgotten in a few weeks. China has endured much more hamulating taunts in the past and reacted surprising little and that went no where, I think this time may not be that different after all.
Look at this on the flip side, if US suffers from a military defeat, will Americans go onto the streets and protest since the entire American identity is about their invincible strength in military's? Not really right? America was able to get through Vietnam although with some trouble, but it got though. It withdrew from Afghanistan last year and no one really did anything.... A lot of Chinese on the internet is still hopelessly worshipping the US after all the hamulating defeats it had suffered in the past couple of years from Covid, Afghanistan, and more, but US government is still perceived as pretty legit by most Western folks.
Let's just put it this way, CPC and Xi's legitimacy is not built on top of Taiwan alone, so one single issue may cause some degradation, but unlikely going to lead to any significant or catastrophic loss of trust that will cause actual turmoil.
But that is just my personal opinion.... Please feel free to challenge me on this one...
What about
3? Honestly I have no real insightful analysis on this one, I think it is not a bad time window. In fact, quite a few PLA high ranking sources have openly stated that they are confident in PLA's ability to defeat the US in West Pacific in a Taiwan contingency for the past 2 -3 years, and PLA's recent behaviors towards the US seem to prove so as well, so if we take such words for granted that the PLA believes it is ready, then maybe it is a good-time window. Who knows.
Finally let's talk about
4. This is an assumption that I agree. I think China has pretty clearly drawn red lines on issues of sovereign safety, and past records do show that when these are crossed China will respond forcefully (Korean war, 1996, Zhen Bao Dao). And given the overall Chinese and PLA sentiment on the Pelosi trip in the past couple of days, I think Pelosi is very close to a red line and the Chinese will probably deliver on their threats, but how serious the threat is, we'll not know.
Finally based on all that, I think if PLA is going to respond forcefully, I don't think it is going to be about preserving Xi's legitimacy or ensuring the success of the congress later this year, but to have a shock and awe effect on the US, its allies, and the world that is serious enough to fundamentally alter US calculations on how they should be dealing with the Taiwan situation with China. But how serious is serious, is it kinetic? Honestly I am not so sure. Maybe we need to keep an eye on whether people in Fujian will be asked to do exercises evacuating to air shelters and general re-call of ex-PLA soldiers.
Well that's all my thought dump in a few posts, please do debate me on some of these..