Easiest way to transfer all actions, settings, column configurations, etc. to a new PC?

[ohrenkino]

See the documenation:

Download and Installation – Mp3tag Documentation

and possibly for MAC:

Preferences and Configuration

You can configure many areas of Mp3tag via the preferences window at Mp3tag → Preferences… or ⌘ , General [Preferences → General] Startup Folder Here you can specify the startup behavior of Mp3tag. None starts with an empty File List. Previous starts with the folder which was loaded the last time you’ve used Mp3tag. Other… lets you choose a explicit folder that is loaded on startup. Genres Use standard genres If enabled, Mp3tag lists the standard genres in the genre field on the Tag Pane…