Use whatever version the Deck picks first, if that doesn’t work then try a different version. I’ve rarely had to force a different version, even with unupported games.

ProtonDB is great, I post on it myself, but you have to remember every comment is out of date by the time you read it. What was necessary 6 months or more ago is not necessarily the case today.

Also GOG has lots of games with native Linux versions and you get all platforms when you buy. They even have a Linux filter.

Windows and Linux use different file systems. Unless you want to install a third-party file system on Windows then you can’t share an SD card between SteamDeck and Windows.

Share a drive from Windows and copy files across your local network in desktop mode on the Deck. It is far simpler.