Books by Pax, Ayoob, Gila Hayes and others - all describe the appropriate views of self-defense usage. Easy to find on Amazon.
So do courses by such folks. I recommend them rather than making up your own inflammatory rules.
If you truly get into it - use Google scholar to find law review articles on using lethal force in self-defense or the excellent book - Killing in Self-defense by Leverick. It is a touch dense for the average gun world prose but truly enlightening.