If it’s only for the games, maybe using steam flatpak can help. So the packages needed for gaming on steam will be up to date (if you have an NVIDIA card it will still be a problem I guess). And install maybe protonup-qt (don’t know if it is still used or replaced, sorry) to manage your proton versions and download the versions needed.

In addition, check protondb website to see if the problem you encounter are known and if it can be solved whether with a different version of proton or a command line in steam launcher exe of the game.

The signature and the random updates issues can be solved (partially) by using the izzyondroid repo. A lot of the applications on fdroid are on it. It compiles from sources, doesn’t change signatures, and fetch updates on a daily basis.

It doesn’t solve all the issues, but it can help