When the game isn't in focus, I would love it to be muted and running at lower FPS

In other games, such as Diablo 3 you can choose how many FPS the game should be running at when unfocused. And it also has an option to be muted when not in focus.

Sometimes I like simply alt tabbing and browsing a bit, but it’s quite distracting when all the game audio is still going on.