Suggestions from a new player to this server for this issue :
1) A lot more policing of /ooc for those that are immature in /ooc with a different penalty for each infraction. First, a single warning via tell, then for a second offense some form of penalty to the character (take 20% of their cash in the bank, so it effects all levels equally), then for a third offense a 2 week suspension, and a fourth offense permanent ban. While this may not be possible due to limited resources of people to watch /ooc, it would likely be effective.
If someone gets a warning, maybe let it roll off the end of a 60 day period. Some people will get warnings due to reasons "beyond their control" such as a family member or friend typing something while they are AFK, so allowing the warning to only last for 60 days means they have to break the rules FOUR times within 60 days prior to being banned.
2) Additional chat channels would probably help quite a bit. I think this would do nicely, as long as someone who was talking in the wrong channel doesn't become the l33t d3wd of "I can talk anywhere I want and you can't stop me." If that did happen, see #1 above for possible ways to have them dealt with.
Channel 1 : /wwc - Worldwide chat channel. This is server wide and to be used for game questions and answers ONLY. Things like "How do I?" and "I'm stuck with this, can someone help?"
Channel 2 : /ooc - zone wide, out of character chat - can talk about anything here, family, politics, it is out of character and designed for this.
Channel 3 : /wwt - Worldwide talk channel. This is /ooc but serverwide.
Channel 4 : /shout - zone wide, to be used for IN GAME chat only about your character, roleplaying events, looking for others to help with killing a mob, etc. NOT to be used for normal discussion (see channel 2 of /ooc if you want that.)
Channel 5 : /banter - Worldwide chat channel. This is /shout but serverwide.
Channel 6 : /auction - This is the auction channel, to be used only for buying and selling.
With the six channels above, people can choose what they want to see.
3) Limit certain chats only to contributors. Lets face it, most adults who are mature can easily donate something to the server. I would have to guess that 95% of those that are the problem are people who are here for two weeks then we will never hear from again. By limiting chat only to those who donate (except for maybe one channel designated for new players to ask questions) you have the "newbie" channel, and the rest of the channels for those who are likely here for the long haul. Note : I like this idea the least of the three, but wanted to at least mention it.
Well, there are my suggestions for possible ways to help the chat problems before they go spirialing out of hand. Feel free to use what you wish, and ignore anything you don't like!
See you in the game,
Zyekad