I have had these kinds of conversations too many times to recount. It always seems the person who is questioning using deadly force in this kind of situation is asking that we consider the thoughts and feelings of the person committing the forcible crime.
However in a situation where actions can be the difference between life and death, I would think most people are only concerned with perceiving actions, and responding to those actions.
Taking all of the danger out of the situation by looking at it from the distance of your couch using abstraction is all well and nice, but it ignores the very real danger brought to your neighborhood by unknown criminals.
No one knows their intent, no one knows their motivations, no one knows their character. Asking us to consider these things with no information about these factors from our comfy couches is all well and nice and we can have a nice abstract conversation about morality, but it is a different thing when you are the person and you are in that situation.
Actions are all that matter is such a situation. Breaking into a home is a violent action, it takes effort, intent to do harm, and offers many potential motivations which could end in a tragedy far worse than the death of the perpetrator.
Day in and day out we see in the news old ladies being raped by violent intruders, criminals pretending to the FBI and breaking in a door, armed men break into a house and shoot the occupants for no real reason. These may be statistically unlikely events, but statistics be damned when you are the person watching it happen.
IMHO a far bigger concern is that no one will choose to help you when you are in that situation because they want to, "mind their own business", or do not want to end up being questioned as if they are the criminal because they are forced to kill an intruder and then need to scramble to prove they feared for their lives.
Community means caring what happens to your neighbor. It means they look out for you, and you look out for them, and again its just my opinion, but when the members of a society stop getting involved in correcting injustice, when citizens are too scared of liability, or do not foster the level of personal responsibility to get involved to place a citizens arrest, or to even just challenge the crime, then the society is harmed for it.
The police, and authority is general is a cop out of personal responsibility. It seems many want the police, and the government to do everything for them in order to shuffle off the responsibility that each of us have to each other and to our communities.
Even the criminal when they enter into a house, get wounded and then try to sue the owner is saying he is not responsible for his own actions. He wants the government to be responsible, he wants the law abiding citizen to be responsible, he wants his child hood to be responsible, he wants anything and everything other than himself to be responsible.
I do not accept this line of thinking. I think it is what degrades society, and removes accountability.
/rant