To your third:
How exactly do you define "provocation"? I'm curious because you seem to have a very lenient definition when talking about police using deadly force. This is remarkable to me when there have been a number of highly reported incidents involving police shooting a civilian without provocation that warrants deadly force (by my definition and video evidence). Here are a few to consider:
1. Tamir Rice
2. John Crawford III
3. Levar Jones
4. Laquan McDonald
Seriously, I could go on. It happens far too frequently that Americans are killed by police firearms when they are not posing an immediate and credible mortal threat. Sadly, there are too many high-profile cases in which cops fire before even bothering to assess the situation. Videos of these incidents abound.
Now, I assume we all agree that police are charged with serving and protecting their communities, right? I believe that also includes suspects and criminals. The bar for determining provocation that warrants deadly force should be very high.
If we are being rational and reasonable, I think there are behaviors that we can agree are not provocations of mortal danger. A few such behaviors:
1. Running away from police
2. Verbal altercations
3. Suspicious behaviors of any kind that are not posing credible mortal threat to other persons or officers
4. Reaching for waistbands (of what are too often excessively sagging pants that frequently need to be pulled up)
I think it is reasonable to have a civil, national conversation about better training for police, and a national charge and expectation to keep every potential suspect alive until a situation is properly assessed and resolved.
If ranchers in a standoff, or bikers in a gun battle, can make it out alive, I think many more can, too.
Funny story from my childhood in Southern California, around 1990:
I was playing in the yard with my toy gun. I hated the orange cap at the end of the barrel and had pulled it out with pliers. It was a metal rifle. A cop came down the neighborhood street, and I took cover behind a tree and pretended to shoot, as if he was my new imaginary enemy. He slowed down and stopped in front of the yard. I was within earshot, so he called out to me in a friendly way. Asked if I was shooting at bad guys. I nodded. He asked if I'd like to see his gun and might be interested in a trade. I thought that was cool, and ran over to his car with my metal toy rifle. He opened his car door to me and stepped out, asking if he could see my gun. I handed it right over, and he invited me to sit in the drivers seat of his squad car. Looking back, I'm sure he was checking if I had a real firearm. He then showed me the shotgun he had secured between the front seats. He talked to me about being careful with guns. Then he suggested there were some bad guys sneaking around my house, and I should go get them with my gun. And I ran off to chase them down.
I shudder to think what would happen to my 12-year-old in the same situation today.