I'm not sure many people remember as often as I do that they're 'typing in chat' and often type out sequences of shortcuts only to have them displayed in chat, or think that they properly clicked the chatbox(a pain in the arse!) just to then have the "Leave Village" sign or a skill or two pop up, but it can be really annoying.
Most MMORPGs (Not that this is one) for the most part gain much by the chat, it relieves grind to chat with people, and having a great chat system that feels much more natural can make even the worst games very, very fun.
A common example I come back to every time is MapleStory as far as chat system's go for MMOs because even though the game is so plagued it's for the most part a perfect chat system for one with a game built around it. Taking some clues from games like this that are praised for their chat system would be an awesome idea.
Some (possibly) fast fixes that would help to see around I could think of to start: Enter Shortcuts to chatting ('Craft' would need to be moved to something else), and to end chatting such that if I wished to type in "John went to the bar", I would simply press: {Enter}John went to the bar{Enter}{Enter}
The first Enter initiates chat, the second sends the sentence, the third uninitates chat.
I'm not sure how much of this could be done simply with an opensource client but I think a good deal of this would be solved with a way to simply create your own shortcuts/hotkeys via GUI, if it's possible via editing the client it'd be nice to simply see one with it as a 'test' (for public appeal among other things) before actually being introduced.
There are a few other problems I've had with chat but most of them are often brought up anyhow: colors, font size, un-expandable chat box
Apparently already suggested, here: viewtopic.php?f=5&t=6081