Question about printer repairing permissions Tried installing printer driver software. There was some message, that might have been about "software for the printer was installed incorrectly", then asked if I want to repair the thing, I agreed and it started repairing permissions. In the end it still didn't properly work.

The question I have is - what does repairing permissions mean in this context? I read articles and definitions and don't get it in this context. Did it mean the installer simply moved the driver under Mac's command or something?
Normal Mac thing, nothing to worry about?
Fixing permissions simply means that macOS is going through it's files and ensuring that all the files have the correct ownership and permissions (to read/write/execute). 

For more detailed explanation on permissions, have a look at this article.

Usually, when something isn't working right, "fixing permissions" solves the problem because the system process that handles the operation (like printing) didn't have the permissions to access the necessary files.

In your case, it sounds like you have the wrong printer driver.