I don't know exactly why the distance from the fulcrum changes how weight is distributed. I think it has to do with center of gravity, but I couldn't explain it without taking physics first. Or reading about it. The closer to the fulcrum an object is, the less it affects the balance, and moving it farther away makes it influence the balance more. This can be balanced itself, having a heavier weight and a lighter weight be on different places on the platform to simulate each other's weight.
Customizing materials is useful for being able to switch out the look of an object without needing to go back into a modeling software, as well as it being a fairly easy process to apply a texture. Textures can be used in testing phases to indicate what objects are what type of object, like yellow for something climbable, or red for a physics object.
An example of balance, a close attempt, and a material example.
A series of images depicting a single attempt to get pancake on a plate.