My new to me 1996 will sometimes blow hot air out of the footwell even when the climate control system is off. To turn off the air I must turn on the climate control system and then lowere the temp control. Is this a common maxima 'feature'

 

yeh, that should be normal, nothing to worry about, You can change that by lowering the temp, or the direction of air.

 

You might want to try pushing the circulation button to on, so the light is on. If you push that button when the climate control is off, there is no air flow.
I hope that makes sense.

 

mine does this too, i can sometimes get it to stop..
it seeps hot air from the feet when its turned off
i try and change settings so that it changes the air flow but sometimes that just diverts the air to come from somewhere else

 

just hit the circulation button