Viewing trade chat and seeing annoying or abusive people bringing their drama and viewing normal chat and seeing someone making their own advertisement for something outside of the games interest like selling gold for cash, leads me to believe that you haven't found the right way to deal with the situations when they arise.
So far its been take a snapshot and send it to contact us, or if a [gm] is on or a well connected [gs] is on then we might get to see the offending persons words vanish, or use our chat command option to block the person and still see all of their words outside of trade still exist.
I propose a solution better than all three examples while still keeping all three examples for us to use.
I would suggest a mute option for the players words (any other player could use.)
Example: Offending player has set up a shop and is advertising something I don't want to see so I right click the player and a mute option comes up with all forms of chat types available to mute and a check off box for each one of them and a check off box that simply states all. I click on the all check off box and while the character remains their all their words on the shop get replaced by the words "MUTED PLAYER!" Furthermore Muted player! hovers over their head as long as i continue to mute them. All forms of their chat types are muted too. No whisper, normal, yell, area, trade, union, or guild speech is read from them while muted.
If they get 3 other players to mute them as well than they are banned from game for 1 hour for the first offence, 24 hours for the second offence and 7 days for the third offence, 1 month for the fourth offence and finally just banned for the fifth offence for a year.
Their would be a cool down on the offences too. after the player has logged back in after the 1 hour timeout if they are good for an hour of game play (Good meaning They haven't been muted in any way from another player) their 1st offence disappears. Cool down on 2nd offence would be 24 hours after they log in to game, cool down on third offence would be 7 days, cool down on 4th offence would be one month, and the fifth offence doesn't need a cool down because a year of peace from that person would be good enough.
Their Ability to trade with another, request battle with another, or another annoying thing that they can do could also be treated with the method above and solve a lot of problems for everyone involved.
If the, "I was muted wrongfully and I want something done about it" comes up; all that needs to be done is this, An email stating that it was done in a majority fashion and the people involved in your situation felt that you needed a time out, we are sorry if this interfered with your game play experience. here have a coupon good for 500 AP the next time you purchase AP.