Sometimes I like to see a lot of information for one (or more) of my files. I find the consolidation of the Tag Panel to be quite useful. Here's what mine looks like, currently.
You don't show covers (or lyrics)?
Covers are just below the crease. I'm not as intent on the lyrics in the tag panel, though.
1] You are using too much space for Year
2] What happens when there are two Labels?
3] What happens when there is more than one Catalog number?
4] What do you use that Grouping for?
5] Do you use Comment for storing info of the kind that we see in this example: a desciption of a version of a given album / single?
I'll try to answer in order...
1] Just the way it fell in the panel. It fits...
2/3] I'll end up with 2 directories for the albums.
4] It's a method of indicating a playlist that I've put the file in at times..
5] Yes. Then I'll perform a refactoring of the album directory, formatting the _FILENAME:
..\$num(%year%,4) • %album% %comment%\$num(%discnumber%,1)-$num(%track%,2) %albumartist% - %title% ~ %_bitrate%