This is the problem with id3 (specially v2) tags, and how it evolved into having so many information that really isn’t need with mp3s.
Anyways, I skimmed through your post (sorry its way to long to read).
In regards to the artist field, it should by default sort by the artist tag. I think “Album Artist” “Conductor” “Original Artist” “Lyricist” “Original Lyricist” “Composer” are all ignored. As for “contributing artist”, I cannot find this field? Cept these fields are taken from WMP.
Winamp has some differeing fields like “Producer”
As I said, this will probably be a problem with consistancy since almost any info can be made in id3v2.
I believe your problem is with WMP (and a lot of other online music database media players like Rhapsody). The way they handle organization is by artist, THEN album, but the problem is artist can be anything in one album.
Suppose I had one of Timbaland’s album, and within that album there are tracks with artist fields “Timbaland featuring Nelly” and “Timbaland Featuring Timberlake”. Well even though they are in the same album, they have different artist fields, and get grouped in their own because of it. Hence the weakness of this method of organization and databasing.
