Add Columns in Discogs Search and other problems

Hi There!

I'm using mp3tags feature to complete my Tags.

Is there a way to add columns in discogs Search?

I only have Artist, Album, year, format, Label, cat-no., country

For identification I need Lenght of the Song.

Also I have the Problem, when I choose an album I only can select the first song, for example when I choose Track A2 or B1, the right title is shown on the left but on the right side there is no association, so no title is written in my incomplete Tag.

Also I have to check each file individually, I cannot select lets say 10 files and click one by one, when I change the first file all other tracks will have the same tag.