Some of your points were true 10 years ago but not any more.
China has basic food secuirty, ie. there's enough rice and grain to feed the population. What it doesn't have enough is food for livestocks which means no steak at war time, but hardly a fatal blow. China gets most of its oil and gas from Russia, given what we know about Putin it's hard to see Russia cut off the pipeline to help US. Even if they do, I don't think it's enough to stop the war machine, 1/3 of China's electricity is generated by renewable energy, they also have a lot of coal, the reason they built the gas pipeline with Russia is to move away from coal.
Chinese navy is no longer a brown water navy, the 3rd aircraft carrier will be battle ready in the next couple of years and the 4th one is being built.
The assumption of US and allies completely blockade China's coast is very unrealistic, it's more likely the allied fleet will try to stop a blockage of PLA on Taiwan, which won't last a few months without external supply. And in term of drones, China is also a big player in the field. I don't think Taiwan has advantage on that. Ukraine can wreck blacksea fleet because it was a very out of date navy, unfortunately you can't say that to the Chinese one.
Difficult to land might be the only defence Taiwan has.
The assumption of US and allies completely blockade China's coast is very unrealistic, it's more likely the allied fleet will try to stop a blockage of PLA on Taiwan, which won't last a few months without external supply. And in term of drones, China is also a big player in the field. I don't think Taiwan has advantage on that. Ukraine can wreck blacksea fleet because it was a very out of date navy, unfortunately you can't say that to the Chinese one.
Difficult to land might be the only defence Taiwan has.