If you go to the mfr website and pull up your model, you should be able to look at the install or spec documents and that will show you specific measurements. They also may have that listed in general information for the model.

I remember a model I was thinking of getting (GE?) showed 30" to the bottom of the cabinet. But you'll need to get the information for your specific model.

Yes. Check the instructions for your particular model but also keep in mind that the more powerful the range, the further you have to mount the mw. Some ranges produce too much heat which messes up electronics and can even melt the mw.

As far as aesthetics go, I installed mine 24" from range because I'm tall and like to be able to see into the pots on the back burners. If you mount the mw too close, you'll have to stick your head underneath it to get a good view.