Great post; its VERY VERY important to know your states use of force laws. I would suggest if you are reading this, you own and gun and you don't understand your states use of force laws you correct that ASAP. If you don't own a gun I would suggest you read up on your states use of force laws right after the laws governing posession/transportation if firearms.
Illinois for example has very good use of force laws, better in some ways than many "gun friendly" states in we get good civil immunity.
(b) In no case shall any act involving the use of force justified under this Section give rise to any claim or liability brought by or on behalf of any person acting within the definition of "aggressor" set forth in Section 7-4 of this Article, or the estate, spouse, or other family member of such a person, against the person or estate of the person using such justified force, unless the use of force involves willful or wanton misconduct.
Nothing a Cook County jury couldn't ignore but its better than many states who have no written law on immunity. There are ways around most such laws; this famous California case as an example.
A Northern California homeowner who police say survived being shot in the jaw during a burglary is now getting a "punch in the gut": The burglary suspect is suing him for returning fire.
The Marin Independent Journal reported the suspect alleges that Jay Leone, who is 90-years-old, negligently shot the intruder.
In that case the bad guy was trying to sue claiming negligence
; something that the homeowners insurance may have to cover.