>China can't feed itself... China runs on oilThat's only a problem if the rest of the world sides with the US in a US-China trade dispute. There are plenty of net exporters of oil and food who would be very happy to sell to China and would be rather pleased to see the US get a bloody nose.
>All we have to do is no longer put merchants heading toward China under the US navies protection and the CCP will be in serious trouble very quickly.
China has a large, modern and highly capable navy. They are perfectly able to protect their own shipping against piracy or any state-level actor that would be insane enough to start a naval war. In the event of a direct conflict, the American navy is largely defenceless against the Chinese ASBM capability.
The US relies on China for convenience, not for survival.
US hospitals would rapidly degrade to third-world conditions without imports of Chinese-made supplies and materials. COVID-19 has revealed the fragility of global supply chains and the position of China as a manufacturing superpower. If you need a sufficiently large quantity of pretty much anything made, you don't have many options outside of China - doubly so if you need it in a hurry. If China decides to tighten the noose on American consumers, you're going to immediately see severe shortages of even the most basic goods.
A total trade war between China and the US would of course have a catastrophic impact on US export revenues because of American reliance on outsourcing - US sanctions on Huawei have had a significant but manageable impact on their smartphone business, but Chinese sanctions on Apple would be catastrophic.