Enable Do Not Disturb in Notification Center when certain app is open
Sure. Create a Keyboard Maestro macro that runs when the app launches and runs an AppleScript to turn DND on. 

Then create another one for when the app quits which runs another AppleScript to turn DND off.

AppleScript can be found here: http://m.tuaw.com/2013/02/04/applescripting-notification-center-scheduling-do-not-disturb/