Lavi's luck isn't really that terrible. He WAS overusing it, and if it had broken before, it still would mean that he'd fall to his doom. I will admit that his love life doesn't seem very lucky, though - Eliade was taken, Sachiko never paid attention to him in that way, and Lenalee and Allen definitely have something between them. So he followed Chaoji, Kanda, and Krory to... the dissolving Ark. Wherever that other dimension is.
Cross and the Earl know each other somehow.