Well I was helping build a lobby on Ivarice server with Thinkdevoid, sowwie not out yet. But basically he had trouble setting up multiworld portals, and in the end had to remove them completely. Hopefully that does not happen here. But I also understand how the markets and such could take time to do since I helped the Ivarice server apply 30+ items (took about 2 mins each) not to mention having to restart if you mess up
On Team9000, and Ivarice they both have a "Beginner quiz", that helps filter out griefers. Basically it spawns guest in a room with several doors, each door associated with questions and last door is a secret password (only one works). If player goes through the wrong door they will spawn at the start/or have 1-3 chances before getting temp ban. Signs will say to go to the forums to find password or a "welcome" message will appear and inform the player. The password can be found on the Forums.
I realized this would help even if there was a "guest only" world. All guest are not griefers. A player who is a member before they join will have to take the quiz. Obviuosly the Trusted+ are . . . trusted.
I hope this helps Opti with any griefs in the near or distant future