I can turn off all HUD displays, and I can turn off game state HUD(ping,etc) specifically.
but... Is there a way to only turn off the messages window (and still see the radar, target/lead and top command icons)?
the messages are in the way, specially when sniping the messages overlap on top of the sniper rifle's squarescope and makes the crosshairs difficult to see.
Sometimes I press 'o' for the objectives list (which is blank in mp). This worked in 1.2 and since it was smaller than the chat window, it would not block the sniper window. I'm not sure whether this is the case in 1.3 but its worth a try. Also, you can make chat messages go away quicker by checking in addon/config/gameprefs.ini. Pressing escape will bring up the in-game menu. Pressing escape again will return you to your normal view and the chat window will disappear.
I had this trouble yesterday. I tried to snipe and I couldn't see. If you hit o twice I think the box goes away completely. But unfortunetly, its not permanent since when a new message is sent or if a new event occurs.... it comes back. I don't know how to make it stay off. But that hit o twice thing usually works long enough to snipe someone.