-Colored Text for common phrases like GG, Cya, bye, gn, and ty.
-Remove Gray and Light Gray from colored text formatting
-Command feedback for teleportation/warp/home (Player has teleported to you)
-Commands to accept of deny teleport, to help players on Minechat or Chatcraft
-Enchanted sheen for items such as FUN bow and timber
-Change disable mob spawning to a on time fee to get the feature, as changing claim sizes breaks it in its current state
-Show your current position on the leader board, as compared to the leaders
-Show more positions on the leader board, 5 perhaps
-A method for viewing where other players claims are, perhaps as a modification to /viewclaims or some sort of ascii map, to ease up on accidental claim blocking
-A mail system to send messages to offline players
-Disabling &k, &m and &n to help boost rules compliance with /nick
-Separate message for when players change realms vs logging off
Feel free to add more to this pile in the comments, I'm out of space!