Guys,
Apologies for the interruption from a lurker, but a couple of things come to mind. First, this is an amazing project. I really like the basic design and the modularity. There is definitely a lot of creative talent.
Second, I am afraid you are starting to go off into the weeds. The first rule of these types of projects is build something that works. Once you have a working prototype, then start getting creative.
I like the western theme, I think it would work well as a basic ICB type machine. What worked well with ICB & ZP was the use of art to set the theme and let the player come up with a reason for putting the balls in the holes. Personally, I would be happy to have a working ICB clone with a western tavern theme. Call it "Luke Warm Beer" and I would willingly fork over cash for a kit (since I don't have a CNC machine in my back pocket and probably never will).
Once you have the basic machine flipping (dropping?) then it is time to mod it out. If you spend too much time trying to design cool add-ons you won't have anything to add them on to. Build the basic machine. Bulletproof the software. Then pick a theme and get the art.
I like the way the Minions guys are building their pin. They started from a working pin and started to adjust and rework it. They didn't try to create the art and the theme and then go looking for some hardware to slide under it.
As I said, I love this project and if I had access to the tools, I would probably be neck deep in trying to do something similar. I would just hate to see it get derailed by trying to work themes in before there is a working prototype.
Return from interrupt. The above opinions are strictly my own. Your mileage may vary. Close cover before striking.
ken