I'm sorry you're having issues! The Linux version is provided "as is" because I don't know how to troubleshoot it for all the various distros. I am not a Linux person and have only confirmd the game runs on my installs of Ubuntu and Fedora.
For the smallness problem, there's an option in the gameplay settings called "board zoom" you may want to try toggling on.
It might be worth trying the windows version through wine or redeeming your steam key and using proton. Otherwise, I hope you find a fix for your system.