Tri-Pact Control - Radio Interface [TANKS]

[adt22-at-drexel.edu]

Looking at this:
http://www.rctankcombat.com/articles/speed-control/07TriPactSpeedControl-large.jpg

I've got some stupid questions:

What is the interface between the radio and the snap action switches in the tri-pact 
controller?

I think I've got SSR's on the brain and I am expecting to supply some current to the 
switch to enable or disable it.  I suppose that's an alternative.

How bad is it if all the switches are activated (up-down, left-right)?  I am hoping 
that isn't a no-no (does it just lock all the motors?)

Thanks,
Amir