As the list feature can contain both albums and tracks, I’d love to see an option where you can put non-single tracks to lists, too. You can rate individual tracks on the album, and there’s even a webpage dedicated to each of them. I don’t see a reason why you shouldn’t add these non-single tracks to the list. It’d be helpful for those who create “best songs of the year” lists.
The track cover can be the same as the album’s, and the rating can be the same as what you rate it in the first place. What do you think?