"China is net food and energy importer."
Chinas wealth is based on neither. So what? Many rich countries import energy. BTW, China is serious about fusion and thorium reactors.
" China has an aeging population, and it's already a rapid shift."
Most countries do and this can still Change.
"- China's infrastructure isn't as well built as other countries and it will start degrading, and maintenance is a pain."
I am sure that the huge and extensive bullet train network in the US won't show any sign of aging very soon. Just kidding.
"- Supply chains are moving elsewhere."
Unlikely, the Chinese type of clustering is hard to replicate. Lower things like textiles and assembly might move to Vietnam. Owned by Chinese companies.
"The US controls space, and will solidify it's grip in the next 3 years. "
Yes, sure. Good luck with that. Sure the Russian will also we happy about it. If I remember right, the next version of the S400 System can even shot satellites out of orbit, but I may be wrong.
"What do you do about automation, if it wipes out jobs for all the restive angry young men?"
Chinese will be leading in automation. Not sure about the angry young man. A Chinese person seems to be happier and more able to endure things in my experience. Strangely, I found many very sensitive to hunger.
US vs China would be an interesting war. The US has very to no experience in fighting such a war. What most Americans don't know (and actually phrased to me in this way by my US professoer): The second world war was a German-Russian war in Europe. The US industrial might helped Russia, but the US fighting was negligible. Russia lost every two days as many people as the US in a ten year war against Vietnam. The US has never fought an equal opponent. Just as a word of caution.