Well in the comics IIRC the suits were neuro-linked so most of the basic functions were autonomic so to speak and the rest were a little mental control. And Pepper has that when she needs it.
That said the move-with-the-body functionality can be accomplished using simple pressure sensors ala the Starship Troopers (book not movie) suits where your body moved, that pushed/activated sensors, and the suit moved with you to get out of the way. So to speak. :-)