I used to play on a server about the same size as this and a bit similar, except it was a factions/roleplay. Anyways, one way it was similar is it had different chats like auction local and general. It also had a help chat. In this chat you could ask any question, and would typically get a reply from a staff or other experienced player within seconds. This would be useful in ecc, since often times a simple question from a builder is lost within the large amount of global chat. I don't know much about plugins, so IF this could be possible, I think it would be a good improvement of chat management in the server.
I think this would be an interesting idea to implement. Having "/ch help" for questions and making it a different color from "/ch g" would make it easier for everyone to see who has a legitimate question. However, this channel should be monitored just as strictly as "/ch tr" and "/ch auc" when it comes to chatting within it. This channel (In my opinion) should only be used for questions directly relating to the server. I would say that only staff should be able to see this channel, but they aren't the only ones capable of handling questions. If a question is urgent enough that you need to speak to a staff member directly, then that is what pm'ing is for.