I think that would be OP to make a check box in the mobs element that says "is this mob controlable?", if you check yes, you can use another check boxes as "can jump? (example: horse)", "controled in water? (example: boat)", "its needed an item? (Example: pigs and carrot fishing rod)", "need blocks to work? (Example: minecart and rails)", and more if you can think more.
Thanks for see.