It looks like you've got all the timing options covered pretty well. What are you thinking in terms of getting values into the microprocessor? Pots? Digital display? Programming mode?
Your ferris wheel example got me thinking about the accessory feedback to your circuit. Maybe a switch input or two from the accessory for limit switches or a reed switch. I realize that this may be beyond the scope of what you are trying to do with the general nature of this device. But timing alone can be a tricky business for certain applications. Generally I would say that most accessories should handle their own special circumstances on their own and not rely on external circuits for their operation. Just brainstrorming here.
It's good to get microprocessors involved in this hobby. You can do a lot without dedicated circuitry using these great little devices. I just ordered some Arduino Nano's from China for $2.40 apiece. They're just too powerful and inexpensive to ignore.
