roller is speaker fader front-rear; switch with little man is rear window lockout (I think); lets driver stop rear windows from being moved by the local control.
The high idle on my car was returned to normal when I replaced the idle control: a black box located under the carpet in the passenger footwell. Also, vacuum leaks can be a causitive factor: check the vacuum lines in the automatic climate control including damper door motors (2 of mine were completely rotten). Don't forget the rubber seals in the air intake manifold and the seals at each fuel injector. Hope this helps/encourages you. Never give up!