As I understand it, it is not over. There should be more Worlds opening up and Worlds that we have visited will have new connections (ie Monquista and Valencia). We don't just know when this will happen
One-Eyed Jack has said that ships and houses will not be transferable between Pirates in the same account. He has said that ship equipment will be transferable in the future, just not yet. If you want to see his posts, do a search for "One-Eyed Jack".
At level 50, you have reached the present experience cap. When a new area opens up, there should be a new experience cap.