Wow hangs on updating blizzard launcher
There are other bigger things but I don't want to spoil that right now.
So I took 2 screenshots here because it's one of the larger tabs So lets go over the options in this first screenshot So until about the first red arrow I don't recommend messing with anything.
Blizzard Launcher was a utility application introduced with patch 1.8.3 to ostensibly provide news links and a minimal set of pre-launch configuration options for the actual game and the patch downloader.
Behind the scenes it would also theoretically provide some measure of scanning and protection from trojan viruses and third party cheat programs.
The 2nd part you can see the option for When I launch a game, by default it sets it as keep the window open, I personally would choose exit completely.