Which version of Steam did you install? I think that's a quirky one where the Flatpak version works better in some cases, but check out the native if you're already running the Flatpak version (there are pros and cons to each).
9070 XT is new enough that driver issues aren't surprising. Periodically check in for updates drivers, more than you would usually.
I recently played through Cyberpunk without any compatibility layers and it worked flawlessly, and I've played Hitman:WoA (I know a different game/version, but closest I had) using only the Proton compatibility. (It runs native, but has some menu issues.)
I bring these up because I was running into similar issues as yours at first when I switched to Linux, and it was all caused by the Steam version I had installed. I switched that, and everything else fell into place.
Best of luck!
Try uninstalling Steam (or keeping track of which one was already installed), and trying one of these methods. It was over a year ago I last did this, so I don't 100% remember which version I ended up using but believe it was the Flatpak version that worked best.
For graphics drivers updating, MintOS has a GUI interface for managing drivers which is actually pretty nice. Try searching for Driver Manager in your system utilities. Other than that, you can manually download official AMD drivers from them directly here. I'd recommend looking into that process for Linux a little more before going that route, as there are a few CLI commands you'll have to use.
As for updating anything, yes it will mostly be done the same way you installed in the first place if you used the CLI. Try the following:
sudo apt-get update
sudo apt-get upgrade