i’m on vacation for a few weeks, but roughly, sonic analysis is used a bit for artist radio (to find similar artists), track radios, album mix builder, and the sonic adventure.
forgive me for saying this, but i think maybe you might be caring a bit too much about how the sausage is made. if it tastes delicious, eat it! 
i’m sure others can fill in the other basic questions you have around radios.
