First eliminate the thoughts of shooting to disable or wound because of the caliber you were carrying at the time. Many a person shot with a .22 was killed instantly because the bullet hit the right spot.

Every situation would/could be different dependent on your state law, your level of training and the actions of the suspect. If your state law says you do not have to give a warning, you can shoot through the door and so on do what you feel you have to do but realize when this happens and you then find out you have shot your neighbors 12 year old who was banging on your door to alert you of a fire at his house you also have to live with the aftermath.

Everyone has to make their own decisions in regards to the given situation. As for myself I will identify my target before shooting, give a warning if appropriate from a position of cover and will use whatever force needed to stop the threat from harming me or mine whether that is the simple display of a firearm and intent to use it to multiple rounds fire with a reload if the threat remains.

Once you engage, engage with the purpose of shooting until he stops whatever he was doing that made you shoot him in the first place. Whether or not your state has a castle doctrine or not just because you can shoot, should you. There have been several high profile cases where the castle doctrine and stand your ground laws have been questioned and challenged.

If I find a person in my living room at 0300 my intent is to stop the threat which includes the suspect leaving my home willingly to be apprehended outside away from my family. If he is armed all bets are off unless he chooses to comply same if unarmed. If he complies great if he poses a threat then he is dealt with accordingly.