I believe that implementing a favorite world feature would be good for not only the players' convenience, but for the lag on servers, as players would hopefully not default to World 1 as much. The feature might include a separate tab in the worlds GUI or simply their favorite worlds on the bottom (can be toggled by right-clicking.)
Another idea I had is to allow players to see how individual equipment slots are affecting stats, so that it becomes much easier to track skill points, instead of scrunching the two together with the only indicator being "This skill was modified by your equipment."
That's all my ideas so far. Thank you for any consideration. Constructive criticism or feedback is appreciated.