There seems to some obvious things left out or not addressed:
1. All bullets should be kept in the upper right hand breast pocket. A true law man or serious gun owner only needs one.
2. Attempting to break in is not breaking in. I would guess the homeowner who shoots while somebody is in process of "trying" to break in vs. somebody that shoots at an intruder that had already entered the premises are two different situations.
3. I like what Viny wrote about thinking it through. Perhaps even go as far as practicing to the point of even waking oneself up at night for a dry run would be a huge advantage.
4. Prodigal Punk is spot on. The instances leading up to eventually having somebody in your sights is mind blowing beyond belief. I have been involved in two situations while in the military. One just seconds away from discharging my weapon, one other prepared but luckily not to the brink. In both situations I was adequately trained, with clear guidelines and rule of engagement. Neither situations involved being startled in the middle of the night from REM sleep. In that situation the heart rate and adrenalin would be seriously off the charts. The average homeowner would have about a zero percent change of reacting rationally under those physical and emotional states. Pretending to be able to assess the intruders intentions and default to the appropriate response is silly.
5. Any would be intruder undertaking such endeavors is taking on extreme risk that the task will end very badly. It is impossible for me to have any sympathy. Having a crappy *** life is no excuse. Many people have crappy lives and stay crime free.
6. They call it deadly force for a reason. If you are going to use karate, rubber bullets, a 9 iron, or arm wrestle the dude for your stereo set, you might as well get a dog. Dogs do strange things to people, especially those doing something they shouldn't be doing. A well trained protection dog would solve many problems in this scenario.