I like this idea for darkrides. I would love a simple but indept system for objects to controll one another. I personally had an idea involving anamatronic characters being able to "interact" with certain objects. This could tie into your idea quite nicely. When interacting, an animatronic would play a sound effect and animation, while looking at a nearby object within sightlines. This would than also send a message to that target object to also play a sound and animation.
Imagine for example a cowboy anamatronic that can "shoot" certain objects or a wizard anamatronic that can "enchant" objects. These anamatronics would have special anamations for their shoot or enchant action. In adition to their own animation, they will also controll their target. Many objects would have "shot" and "enchanted" animations with accompany sounds. Lights for example would suddenly go out for several seconds while making a breaking glass sound when "shot". When enchanted, they might change color. Other examples of interactable objects could be underwater fountains or perhaps a table or barrel with some tableware or bottles ontop of it. An underwater fountain system could generate a spash when shot or activate a fountain display when enchanted. A table with an object on it could, using clever animatronics, make an object ontop flip over when shot or levetate when enchanted.
Other examples of interaction commands could be "haunt" similar to enchant but more spooky, "make dance" which makes objects move in the beat of a specific song (this action would be available to speakers, and can target nearby objects) and "look at".
"Look at" would not necesarilly control the target object, but it would be usefull for both animatronics and omnimovers.