That's not necessarily a Launchbox thing, nearly all the emulators I use exit with the escape key. So if you have a emulator loaded and you press the escape key on your keyboard then of course the emulator is going to exit. I have never used a emulator that uses escape to pause a game, games are paused with start on the controller like real hardware, and you shouldn't really need to go into the emulator menus after initial setup, that's the whole point of a frontend in the first place, to hide all that stuff so its seamless loading and exiting to/from a pretty interface.