anti-cheat isn't an issue per se, as long as game developers decide to add the required files to their games (eg what Apex: Legends devs did a year or so ago, around the time the Steam Deck launched, to ensure proper Proton compatibility), but in short - yes, many online games will still require you to dual boot anyways, unfortunately.
i'm no content creator, so i can't recommend good alternatives to the apps you mentioned, however OBS works flawlessly on most Linux distros, so you should have zero issues with live streaming.
oh and i would say driver support is usually better on the Linux side, although I think Debian based distros (like PopOS) might lag a bit behind compared to other distros? this might be outdated knowledge though, so take that with a pinch of salt