How hard or difficult do you think it would be to create a game that has many "Elements" or pieces of machinery that themselves have "Hard Coded" behaviours however the way they react to other things is not hard coded. For instance you could create two "Behaviours" and apply them to two things with a liquid "Behaviour" One would be hot, one would be cold.
No idea what you are saying here.
Then you would take the hot and cold behaviours, give them ranges of hotness or coldness and then code how the "Middle Hot" and "Middle Cold" react and give the program examples on what happens with variations. Then you could apply these two things to a wide variety of others.
Programming is very abstract so it all depends on what the goal is for the implementation and how the whole system will work as a whole. Its difficult to understand what you mean here though.
You could give things a hardness behaviour that would make it (Assuming there's physics) that if you dropped something harder or heavier on another object the bottom one would shatter. And instead of programming how those two specific entities that are hitting each other react to one another, you're simply giving them the behaviour to follow when interacting with other objects that have the same or other behaviours.
It sounds like you're talking talking about inheritance/composition and/or polymorphism, which involves having different objects share traits by being based off of or possessing a root object, and allowing different objects to be interchangeable as long as they have the same interfaces. Such features are fundamental to modern day programming.
As far as games go, however, it gets a bit more complicated due to having to work visually. If you want an object to break into pieces without specifying how to do so, then you would need an algorithm to do it for you. A 3D model would have to be replaced with geometrically divided pieces of the original. A sprite would have to have a similar operation performed, making multiple sprite parts from the single one. Such operations might not look great without some tuning and modifications.
Either way, programming these kinds of things can be easy or difficult based on the amount of detail and features it has.