Take this comment in any way you prefer, but it is not intended as sarcastic, arrogant, patronising, etc. etc.
But maybe you need to find a tagging application that is more "pointy, clicky" than MP3Tag is, the real power of MP3Tag is only 'unleashed' when you do start to use the scripting functions.
Programming and scripting in applcations to automate tasks looks a daunting proposition at first, but once you get to grips with the methods and syntax you will find that many of your "wish list" features can be done in a few lines of scripting
Make use of the user manual (F1) where the scripting functions are explained in non-geeky language and you will be surprised at what you can accomplish in a very short time. Don't be afraid of clicking around the menus to see what does what, make a copy of a few albums and tracks that you can 'play' with so you are not worrying about "What if it goes wrong and I fubar my music collection."