@Mooksie; I see. lol well I guess all that's left to do is just close the chat window. See the little minimize button at the verrrry bottom left side of the chat? Mouse over and it'll say "switch the chat window". keep clicking it until its closed. click again to open. click again to turn transparent. perhaps that may help only thing you cannot turn off is the GM/system message which will scroll at the bottom in red. As well as the announcements that scrolls at the top in white/cream.

I've not played the game for a while to see the "All" message to know where it can be seem.. I think perhaps it scrolls at the top as well like with the announcements if I remember, right? I hardly seem them anymore. Not much people spend money on mega phone like the used to in the past. Well I guess since it's seen as a "System" or "GM" message that's the only thing you cannot turn of because the game may see it as something important you need to know like update or events.

Other than that your best bet is to go to systems turn all chat off there or just close/minimize the chat window. Or both.

Sorry. Have to work with what you have. =(