You could actually try to address the questions presented instead of being sarcastic.
Do you understand that the legal system in this country is extraordinarily complex and there really is no such thing as "the law"? Case law varies from state to state and is modified by precedents in higher courts, which is partly or completely modified by statute. This is different in every state.
Some states allow lethal force to be used in defense of property.
Some states allow lethal force to be used to prevent violent felonies.
Some states allow lethal force to be used to protect the force-user's life.
Some states allow this only as a last resort.
Many states require different standards of proof in exercising a defense in these cases.
All states have statutes that address liability for certain classes of activity such as mining, cattle farming, manufacturing chemicals, keeping exotic pets like tigers or elephants, etc, etc. These statutes assign liability one way or the other depending upon what steps the property owner has taken to protect the general public from the hazard due to their class of activity.
Many classes of activity are left unaddressed and thus fall under the common law.
Many types of traps/hazards useable against burglars fall under various sections of the law regarding weapons, building permits, animal husbandry statutes or housing codes. The rule of law is fun when you have so many laws!
In short, I think the question isnt easily answerable except with the most vague and general of rules:
-In most areas, you can defend your house with lethal force if you are there and cause the force to be applied.
-In most areas, you cannot defend your property if there is no threat to your life.