Automating button presses
This isn't really an electronics answer, since you can't modify the device to simply replicate the button and switch contact closures electrically.

This sounds like consumer products testing to me.  You may want to look at what consumer product test houses do to automate the actuation of devices without modifying them.  

For your application, I would suggest one of two approaches:


Solenoids.  Use direct acting, spring return solenoids for the button presses.  The spring rate will determine the maximum actuation frequency.  If you can tune it for resonance, you can reduce current requirements.  For the toggle, use two opposing solenoids with series springs - i.e. actuate the toggle through the spring such that you limit the maximum force on the lever and don't have to constantly adjust the assembly.
Pneumatics.  If you've got compressed air available, going with pneumatic acutation will allow you to actuate each point elastically (air is compressable, so pneumatic actuators have inherent compliance) and with controllable force (vary the air pressure).  This would mean that you could use a much smaller power supply, as you'd be driving small solenoid valves rather than potentially large plunger solenoids.


Sounds like an interesting project.