I might as well try.
Title: Agreed, "Isle of Carnage", or, with a slight possible chance, "i couldn't save them".
Final chapter: 513, definitely.
Cover: I'm hoping for Luffy in the foreground and Roger in the background (because I want to see Roger on a cover so badly, but it's propably not gonna happen. He has been mantioned by Silvers, however. And to see Luffy, who has apparently lost his crew and the Pirate King together would be awesome). Kuma, Kizaru, Silvers have to be on there, too.
I might try and sketch my idea. If I have time to. I mean, it doesn't come out before december anyway, right?