[Superman]

You can usually check AAVs pretty easy. Wait till it's cold. Take the two big hoses off it. With a mirror and a flashlight verify that you can see through it. The hoses you remove are ones that face each other on opposite sides of the device. Then, apply voltage to it and watch the air passage close.

WUR's are a little trickier. I think you're on the right track though. Stopping the engine after a few minutes and waiting has the effect of heading your engine bay. The AAV and the WUR each have heaters in them that are supposed to work electrically. If not, they still work eventually from engine heat. There is a resistance spec for the WUR, though I don't know what yours is. If you put an ohmmeter across the contacts you might find there is infinite resistance, in which case the heating element is not working.

Yes, if you change your WUR, you will also need to re-set your mixture.