When you delete an old featured creation, it counts it against your featured percentage. I don't know for sure if that's the case with Socrates, but he doesn't seem to be so edgy that half of his submissions would be turned down. :P
That's correct. It's because I delete a lot of my memes. Before I started doing that, my feature rate was around 78% (which was still not very high actually, but it's better than it is now).