Very much enjoyed the analysis, thank you. I know nothing about China, but I know about the technical issues you raise, and some of them are very solvable:
Use a proxy if you travel, have lives in different countries or need to simulate user experience in different countries. (HMA is a good one.) There are apps and content blocked in every country, Western ones too. It’s well worth $5 per month.
Use Google Voice to have a single, permanent US telephone number, just like we all have email. That also means you always have SMS, can sign up for anything that requires SMS confirmation, and, best of all, and aren’t hostage to US telcos just to keep your number. And it’s free.