Crappy covers is not a good idea IMO. It's better to skip those songs.
Can other users edit the playlist, or would they have to redo they whole thing?
It's easy to copy and paste to another playlist. I think I will do that so I have the whole library on my account, if you don't mind. You can also choose to make playlists collaborative.
I have created links on each of these year pages. I think this is great!
I have made my own copies of the playlists and replaced two songs with new links because the old one wasn't available in Sweden. It's Santigold's "L.E.S. Artistes" (my new link goes to Santogold...) in the 2008 list and 13th Floor Elevators' "You're Gonna Miss Me" in the 1966 list. Could you guys check if my new songs are available where you are? If not, I'll probably have two rows for these songs, with one of them working depending on where you live.