I wrestled with this concept of centrally controlling everything when we did our first garage haunt 3 years ago. I had made my first pneumatic props and wanted to trigger stuff with PIRs, etc.
I really liked the idea of centrally controlling everything, but the draw back is you've got to run hundreds of feet of wire everywhere (e.g. getting input from PIR sensors, sending output to trigger props, etc.). And then there's the audio issue because if you centralize, then you're needing to either pipe audio back to the prop or trigger it locally. So central management has it's headaches.
I ended up doing a blended approach that relied on some central management to time the triggering of props as well as used micro controllers at some props that handled the pneumatic sequence and audio play back.
I settled on this for the convenience of overall management as well as knowing that if something were to tank on the central controller, at least my whole haunt isn't down.
In terms of overall management, I used an Arduino that monitored for input and then performed the output control. Admittedly, this isn't the most user friendly cause you're coding and wiring all of this stuff up. So the geek factor is a little high.
