Fair points, though imo the situation is far more nuanced. The Chinese dilemma is that they need to be able to manage the decline in their growth rate in such a manner that it doesn't cause too much internal instability. One of the reasons why China doesn't get too involved in external political considerations is that it is international trade which allows them to continue their own development at such a rapid pace. As the developed world's markets become more difficult to access they are turning to recycling the Silk Road and ramping up the purchase of Africa.
Retaliation against US tariffs has to happen but this will not happen Trump-style. The Chinese are far too pragmatic to jeopardise the long-term for the short and whilst the argument may take a while to sort out it actually strengthens Xi's hand in that a future deal with the US will make China far more able to adjust to the increasing constraints of the West. There has been considerable chatter around the possibility that the Chinese may stop buying US debt but again, it is not in their interests to seriously damage the American and possibly the world's economy.
To my mind, the current "trade war" will not drag on and a deal will be done and dusted (and even partly respected) in a few months at most. Xi will show admirable restraint in dealing with Trump, entirely based on furthering their own interests. The US soybean farmers and a few others will be up in arms, probably just enough to ensure that the Orange one doesn't get in for a second term and the Chinese can continue colonising Africa and sorting out the super-highway to Europe's back door.