First, I do not equate life with material objects, regardless of what they are.
Self defense is not about choosing the action that deals less damage to the rights in question. Otherwise you would make even defense of life a case of doubt. Why should a 85 year old having a deadly cancer be allowed to kill a 21 year old attacker, if self defense is justified by dealing damage which is smaller than the damage caused by the attack?
Self defense is not about comparing the damage the attacker does to the damage the attacker suffers.
That does not mean that if I try to stop someone and they use lethal force, I will not use lethal force in return.
I’m not going to kill someone over impermanent, material objects. Such objects come and go. I personally believe it is damaging to the spirit to have that kind of attachment. Even the religious recognize that; that’s why they shun such attachments.
No normal person is required to act in self defense, especially in the generally fuzzy case of defense of property (i just refer again to the many caveats catholic encyclopedia list, which are absent in case of defense of life) is required defend himself. Not defending oneself can also be the more moral bevhavior. So if you say you will not use lethal force to defend property even if its acceptable, thats perfectly ok (i might do that as well).
But that does not mean that lethal force is in general and always wrong.
@Bill 7154
You are correct to note the differences in secular law. I tried here to argue what the catholic position is and the catholic position does not totally exclude lethal force in defense of property.
In Germany lethal force to defend property is theoretically allowed, but often in practical cases it is often difficult for the defendent to convince the court that first there was no less severe alternative way to defend oneself and to avoid the loss of property (a common point is that the use of lethal force could be threatened first, which often might scare the attacker to flee) and that second the property was so important that the loss had not be tolerated. Especially the later is a quite a grey area depending strongly on the individual opinion of the judge. Therefore in Germany its better not to use lethal force in defense of property.
Regarding the US laws, the caste doctrine laws make a lot more sense than the laws of the state you live in, because they seem to be devised by theoretizing secular college people (namely people without families). Raising ones wife and maybe 2-3 children in the middle of the night to escape silently from ones own house (after all maybe the invader wants to attack your family instead of just stealing something) potentially to flee in the dark through uncomfortable weather in light clothing? And how to check whether the attacker is armed and what his intent is?
I consider such laws immoral, by breaking into a house somebody lives in in the middle of the night, one is already threatening that persons lives.
The only thing castle doctrine laws are a bit too lazy is that some waive any requirement of the defender, if its possible without danger to himself, to warn the invader that he is armed and will defend himself. But i prefer laws that err in favor of the law abiding people instead of laws erring in favor of criminals.