From my personal experience on my server Zenox I can say that it is very difficult to find good and experienced staff at the time to bring the development forward. That wasn't always so difficult earlier but the most of the good developers have left graal so you must be pleased with what you already have.
You should understand that you cannot implement all your ideas with a lame development team (not even if you are really good and do everything at your own) because you need a good, varying and active staff team.
Also the idea with multiple seperate worlds isn't better than having multiple islands on a single world because the player count of each world will be (much) different so the players are seperated too which isn't good for solving tasks/quests together and doesn't promote the communication between them. We also had the ideas of multiple worlds and using modern and classic content together but it has been overruled very fast. So we found the idea of a classic server with better, new concepts and ideas than the other servers have much better.
Also it's pointless to have a mass of things if they are confusing, irritating and/or expect too much of the players. So in the most cases it is better to have fewer but thought through things you can provide to the players that are easy to understand.
These are just some advice of me to help you with my experience
