MAC New User findings and suggestion

Thank you and welcome on the Mac!

On the Mac, operations that can be undone easily are usually not guarded behind confirmation messages. You can always use Edit → Undo or ⌘Z in case you accidentally remove a tag.

It's answered here: Frequently Asked Questions → Can I import data from Windows?

Importing .mta action groups is available since Mp3tag for Mac v1.4.4. Other settings can't be imported at the moment and it's unlikely to be implemented.