Generally, defense of property must be proportional to the harm threatened, and use of deadly force is not authorized: http://www.volokh.com/posts/1176499503.shtml (interesting blog post in the context of "hacking back").
No, actually. Outside of Texas, the exception that proves the rule, you are not allowed to use lethal force to protect property.
As I understand Texas law (which I wouldn't surprise to find judicially nullified someday, like similar Oklahoma law), you are allowed to use lethal force on someone stealing your property after a verbal warning.
Which is in no way analogous to the point you're making. US law very much does not support "self-help" as its called to redress wrongs after the fact.
Weak Castle Doctrine, no duty to retreat in your home, exists in 46 states according to Wikipedia, which sounds about right. E.g. assume you have to retreat from your home in Massachusetts, no matter the current law, case law or circumstances.
Stand Your Ground in 22 states. As in no duty to retreat any place you have a right to be, which prevents second guessing from the calm and comfort of a courtroom. Or as Oliver Wendell Holmes put it in the 1921 US Supreme Court case Brown v. United States, "Detached reflection cannot be demanded in the presence of an uplifted knife."
Because that's what the courts want very badly, at least as of the '80s. Several rounds of the solidly Democratic legislature passing "this time we mean it!" laws and the courts judicially nullifying as much as they could.
In one case I "watched" by reading the Boston Globe as it was tried, a man was sent to prison because he wasn't willing to leave his sleep daughter to the tender mercies of an home invader.
Too many people wonder why Michael Dukakis won only 10 states in 1988; not those of us in the the state who were paying attention to e.g. these judges he elevated to the bench.
In the 80s? It's 2013, man, get with the times and start ripping on Chicago.
In this decade, I'd go to the anecdote from WI last year of the dude who, upon a high school party being broken up by the cops next door, shot a kid hiding from the cops on his porch and wasn't charged.
Castle laws pertain to "Your home is your castle", and maybe business. I'm not aware of any that touch on property, they just make it clear you have no duty to retreat from your home (ADDED: true in 46 states according to Wikipedia), and the better ones allow you assume a home invader is a lethal threat, as you can reasonably assume about anyone invading an occupied dwelling. Otherwise proving that could be lethal to you, e.g. challenging the intruder gets a bullet in reply.
Note as usual all this is subject to judicial nullification, in my home state of Missouri as of 2010 the latter part of our crystal clear Castle Doctrine has been nullified through middle level appeals court required jury instructions. Our higher level judicial appointments are not surprisingly done according to the Missouri Plan (http://en.wikipedia.org/wiki/Missouri_Plan), so the usual suspects control the process, not the people through their elected representatives.