In case you wanted to know what happens to your uploaded songs, I just learned this from @bluermlou and @turntablefm:
Q: If you upload a song, then later remove it from your queue, what happens?
A: The song remains on tt.fm’s servers, but it is inaccessible (I assume this means via search).
I have noticed that if you add a song to your queue, even if the song was uploaded by someone else, the song is still ‘playable’. In fact, I’m guessing the original uploader can delete the song from their queue, hear another person play it and add it back to their queue that way.