Danny, where did you get the picture of my electrical setup???
Anyhoo, yeah, you'd be fine with what you're describing. Basically as long as you have a valve (in this case probably just a ball valve like the ones pictured on melev's setup that Drew showed there), all you have to do is close the valve when you're done, the line pressures up and the input valve closes. Open it up and the unit turns on, close it up and the unit turns off.
Drew, FWIW, what you have pictured there is exactly how I have mine setup, except that instead of ball valves at the end of each line, I have float valves on reservoirs (since I'm somewhat bad at forgetting that I have water on and tend to create large pools of spilled water - see signature
). I just use the $10 humidifier float valves from Home Depot/Rona/etc.