Is it possible to have seperated album workart and song workart and artist workart

No. You can only have one artwork associated for one song.

No, it doesn't store separate metadata in that way. You can set the artwork for your songs. If you group the songs into albums, one of your song artworks will show as the album artwork.

No, it doesn't work that way.

Maybe there is a different app other than iTunes somewhere that will let you pick an artwork for your whole music library, and pick artwork for each playlist, and pick artwork to flash up on your screen depending on what verse/chorus is playing mid-way through the song, but that software is not iTunes. It also could get tedious messing around with all of that artwork and is not something that many people are interested in.