I have a draggable object that I would like to only operate in one area of the screen. I have created another object to act as walls. How do I program the draggable object so that it will stop when it comes in collision with the wall object? I have tried ‘stop force’ and changing the behaviour of the walls to ‘obstacle for pathfinding’ and neither option seems to work. Short of deleting the object upon collision and creating a new object in its exact position, how else can I get the object to stop upon collision? 
You can try platform. Make the draggable also a platform character, zero gravity, no default control, etc.
Oooo, how do I remove the default control on platformer characters?
It is a property. Just edit properties of the object.