Those BattleGround and Arena announcements are always flooding my chat. How do I get rid of them?
When you mouse over your chat window, notice the “General” tab at the top. You can right-click on that, go to Settings, then Other, and uncheck System Messages. This will simply disable them. If you prefer, you can move them to a separate window by selecting “Create New Window” from that right click menu, giving that window a name, and adjusting its Settings to exclude everything EXCEPT System Messages.