"You are required to retreat unless there is no other option."
The same is true here. Unless retreating would put immediate family (wife, children, parents) in jepordy.
You can only lawfully use the weapon to defend yourself, immediate family, or employer. However, you cannot defend a coworker or anyone else. Yes, I agree it is entirely stupid.
Regarding the don't pull(in other words unconceal) the weapon usless you have an immediate need to shoot...well that is the way I was taught at a required course. Obviously, if you drew a weapon and the assailent dropped his (gun, knife, axe, etc.) and ran before you could shoot then you don't need to fire - in fact shooting a feeing person is not allowed. However, you cannot unconceal your weapon without an immediate need to use it (a person drawing a gun on you - raising and axe, etc.). If you were to simply open your coat and show a potential assailent that you are armed - you can be prosecuted for assault.
So, what I was taught was don't pull a pistol until you are ready to fire. Practically speaking, if someone is close enough to you where you are in immediate danger of losing your life, you will just have enough time to draw and fire. Personally, I will do my best to get away from an assailent without shooting. However, if they have a firearm pointed at me in a menacing way, I will take cover (if available) and fire(unless it will endanger others). If it is a knife or axe (etc.) they are going to have to be within 10-20 feet and coming at me fast before I shoot.
I hope I never have to find out. Problem is that even though the law "allows" self defense. The local DA can still prosecute if they choose. So, it better be a slam dunk that you were in mortal peril.
It bears repeating that even if you are 100% in the right, legally, when shooting your gun in self defense, you are almost certain to to incur CRUSHING legal bills just to make sure you prove it the right way to the Grand Jury and/or the Court.
There *are* cases where someone shoots in self defense and the police and DA just nod and leave them alone, but most of the time -- even in very clear-cut cases -- they're far more likely to toss it to the Grand Jury, just so that no one (like the dead thug's family, or flaming liberals) will be able to scream that they let someone "get away with murder" without even an investigation in court.
So even leaving aside all the other possible issues, keeping your life savings is a good reason not to shoot in self defense unless you REALLY, ABSOLUTELY have to.