Thank you for your quick and helpful reply!
That's good news regarding the language selection.
Once I'm back at home, I will try if can get the launcher to work with the suggestion in the thread you linked to. Hopefully that will fix it, but assuming it doesn't, I considered buying the season pack via Steam, as I assume Steam's DRM will replace the Launcher. Or does the version sold on Steam also require the Telltale Launcher and activation via a Telltale account?