Linux Mint has been great, you do run into some issues with games that have intense Anticheat, but for the most part the user experience is flawless. I don’t know about steam OS, but with mint (and I think also for Ubuntu and pop OS) you just install steam, install the game from your library, and off you go it’s just like Windows
Been to china, my advice is to amour up with a few vpn providers, and if you can get a sim card from Hong Kong, it gives full coverage in the mainland with western internet access