Since you're not using it exclusively as an arcade machine, I suggest not shelling it, and simply starting it when you want. Make sure it's set to fullscreen.
I do this all the time with Mala. That way, I don't even have to exit Mala if I want to do something computer-related. I press the Windows button, and can select stuff from the Start Menu or the Task Bar. And my 'arcade ambience' continues in the background.