Quoted from Zablon:
Hah.. you are correct. I've apparently never hit them at the same time and noticed...
As for the orbit and switch under the ramp, they should both trigger sounds (but no scoring). The one on the right makes a kind of electronic "donk" sound and the orbit makes a 'swoosh' type sound. The orbit gate is one way, I think that is really the only reason it is there and they just had it play a sound as you go through it. It could be both were originally intended for more, but in the end they are just there to make more noise.
There used to be a single drop guarding the centre VUK. How they fit it with the other mechs etc I'm not sure as there doesn't seem to be much realestate under there. You can see the spot that would've been cut out in the artwork:
I've always wondered if that switch was meant for more in relation to that somehow.