The effect of "PR" on any of these situations is slight. The Pentagon is well aware that Chinese weapons won't fall apart like plastic toys. Even if that's untrue and some idiot like Trump goes to war against China because he believes the bad PR, there's nothing China can do about it except fight. It's too bad, but how you're depicted in enemy propaganda is one thing you can't do anything about - just be ready to put him in the ground if things go hot.
The effect of PR in all of these situations is MASSIVE. Look at the international reaction to this fiasco! Resentment from the Chinese public and mockery from the international. If the Chinese strategy is for the Pentagon to do the diplomacy and propaganda for them, then they've ALREADY lost! If war started today, then the western press will band together and call China monsters and basically the entirety of the western world, India, South Korea, and Japan will be listening to them and agreeing. Do you know
why? Because China refused to fight in the propaganda space and allowed it to get to this point!
PR isn't a weapon you can just pull out from a box and hope that it works. PR is reputation, built over decades of consistent competency and effort. No sh*t the effect of PR in these situations is slight. China never bothered building up its reputational credibility! It'll be too late to fasten your seatbelt if you're in the middle of a car crash and it's far too late for China to build up enough of a reputation to stop Pelosi from getting a win once her plane's already in the air. Do you know how this might have been fixed? If China had began building up their reputation DECADES ago! If they had an effective propaganda wing! Do you know how they stop this from happening again? By properly staffing and funding their PR wing NOW!
Fire everyone in the propaganda wing. Hire in completely new staff and set them to the task of signaling. Make it clear, and reiterate, that the opinings of some tabloid hack from Global Times isn't the opinions and the policies of the Chinese government. Get rid of the Global Times whilst you're at it, or restructure it from ground up. Global Times is boring shlock with no serious viewership and allowing it to exist in its current state is a liability to the Chinese state and reputation.
Establish a channel upon which the Chinese government communicates with the western press and the outside world and make sure to keep staff on-hand to make sure that they can deliver the official party line and stomp out rumors the moment unfavorable rumors start cropping up. The moment what's-his-name talked about how Pelosi's plane would be shot down, have someone on-staff call him an idiot and communicate the official Chinese state line.
Hire on western-trained journalists who are either sympathetic to the Chinese cause or who are willing to tow the line for the luxury pay. Material support for the secessionists will flow in from mostly western countries and so acquiring the ability to 'speak the language' of the western world is paramount. Use these journalists to spread news of Chinese achievements, explain misconceptions, and downplay Chinese missteps and failure. Encourage Chinese students to pursue journalism in western institutes in the same way that they're encouraged to pursue engineering. As an example, the Goldthread youtube channel is a far better ambassador for the Chinese than Global Times has EVER been.
Show favoritism to certain western outlets, lure them in with promises of being able to be the first to question China on the policies and news, and use that position to build a mutally beneficial relationship with outlets that will give those outlets a business advantage of being the 'experts on China'. Hire on influencers for the same reason and have them tow the party line.
That is the MINIMUM China should be doing. This is all very basic policy in any party-based democracy, and so American politicians and therefore the American state apparatuses are incredibly proficient with this. China doesn't have this type of democracy, and so they'll need to learn.
If China wants more advice, they'll need to pay me hourly rates. I take my payments in euros, steam codes, and body pillows depicting the shipgirl Shinano from Azur Lane.