Here are a couple of ideas me and m10m10(frequent chat user) came up with to improve the chat experience for many users.
Timeout: Disabling the user from sending messages in a room. A better replacement to Gag, as gagging a user sometimes causes more spam than (possibly) stops it, and to actually silence someone.
Co-owner / SR mod: A higher ranked room mod, preferably let the owner choose the SR mod /co-owner powers.
User Nicknames: Allow users to change their name in a private room. Only said user can change their name and their nickname only stays in 1 room.
Pre-recorded messages: Allow users to queue messages for anyone that is offline. Only in private rooms and have a option to be seen privately or by the whole room.