Is it really “bashing” to be suspicious of a country that threatens to go to war with us?
It's "bashing" China to insist that everything from China has to be condemned, such as their solar panels and EVs. The possibility of military confrontation doesn't make everything Chinese a threat to us. In every war there is still some exchange between those warring countries, and there's no evidence that the trade was contaminated because there was a war. In the Civil War the South still produced cotton and sold it (some even to the North), to the benefit of all sides, buyers and sellers. When there were embargoes or curtailing of the trade, everyone was made worse off by it. Though it may be that some of the North embargo effort worked as a war strategy, any idea of curtailing the trade even BEFORE the war had no legitimacy to it. There's no reason to believe that earlier trade happening up to the war was detrimental or did net damage to anyone, regardless of the later decline of the trade.
The most aggressive use of anti-trade policy was that of the Confederacy using its cotton power to intimidate other countries into supporting it, which backfired, making the South worse off. Those who use trade aggressively to pressure or punish other countries end up shooting themselves in the foot, doing their own cause more harm than good. E.g., Napoleon and his idiotic blockade of England. The best policy almost always is to leave trade alone as much as possible, and everyone benefits from the trade, despite the economic benefit the enemy might gain, which is offset by the benefits to one's own side.
There's no provable case where the trade was a net detriment to either side. Rather, it's only paranoia and hate and primitive ultra-nationalist instinct which drives the fanatics on either side to demand an end to the trade.
And if China did go to war with the: how would trade work?
Same as it worked successfully in all previous wars when it was allowed to continue and the fanatics and paranoids on both sides were rebuffed in favor of pragmatism.
translation: We're going to war with China pretty soon = WW3, and so since both countries are going to nuke each other out of existence, it's bad for China to produce solar panels and EVs. And to get ready for this annihilation we need to put more workers into auto production and steel production, even though there's no shortage of steel or auto production.
If you're a die-hard China-basher fanatic that makes sense.
Is there a single example in history of two countries at war; and yet they continued legally trading with each other? (I’m not talking about black market trading).
Some trade continued in most cases, and in all cases the trade that did continue was good for both countries -- both the legal and illegal trade. And when the trade was penalized, that did damage to both countries. And it was especially bad for everyone if the trade was cut off only out of
fear of a future war. Curtailing trade for fear that a war is coming never did any good, but only damage to both sides. You can't name a case where the economy was made better by penalizing trade, even if something like a war made it necessary eventually to discontinue some trade.
At some point you have to set aside your paranoia and hate and fanatic China-bashing populism and just look at the facts. China is producing some good products here which are being condemned by the Biden-Trump China-bashers, even though they can't name one threat or damage from these products. Instead they pander to the whining crybaby auto and steel producers, especially the uncompetitive wage-earners who are hysterical over the fact of their declining value in the market. It's obviously these uncompetitive producers, losing more and more of their value, who are driving the China hate, out of fear of the more competitive Chinese products, using cheap labor and other cost savings. Reducing the cost is a legitimate and fundamental principle of market economics, from which 100% of the population, all consumers, benefit. If you reject the principle of cost savings, you reject higher living standard as something of value.
These Chinese products, especially the EVs, are not only lower in price to consumers, but also are top quality, on a par with the competition. It's only this competitiveness which makes them hated, not anything practical. No one has named anything negative about these products other than the fact that they are more competitive. All the rest is paranoia and hate -- it's shameful that the American public lets itself be stampeded and rallied around these uncompetitive crybabies, pretending that there's some economic need for preserving their uncompetitive jobs and propping them up as a national religious symbol of some kind. There is nothing sacred or holy or patriotic about steel workers and auto workers. All workers/producers rewarded by the market based on supply-and-demand are equally legitimate for the economy, with none somehow needing to be artificially propped up as if they're superior to all the others, like we're propping up the uncompetitive crybaby steel workers and auto workers, as symbolic icons with privileged status, to which higher status they are maintained at the expense of everyone else.
The way we prop up these less competitive auto and steel producers imposes a cost onto all the other workers/producers, in the form of higher prices to all consumers = INFLATION, driving down their standard of living in order to artificially prop up the benefits to the less competitive wage-earners we're supposed to feel sorry for because of their declining value in the overall economy. This 99% of the population, the consumers, are just as legitimate in production as the auto and steel workers, having no inferior status to them, and no responsibility to absorb higher cost and lower living standard as a price to pay for propping up these less competitive but privileged auto and steel workers whose value is declining and who whine that they're entitled to be subsidized at the expense of the more competitive producers.