I get, and to a certain extent agree with your premise that the newsworthy cases of police brutality are most certainly the exception and not the rule, there are two parts of your post with which I shall formally rebut:
While it is true that there are a few officers that deserve jail time (and the do get it most of the time) 99.99% of the LEOs our there are the good guys. They go out every day with a target painted on their back to protect the rest of us for crap pay. I am fine if they want to make sure their neighbors/acquaintances/dates don't have drug or assault convictions. Using that information to blackmail is different, but just having the information is fine as long as they are responsible with it.
I think the 99.99% figure is exaggerated, but I'll roll with it for the moment. I don't get to check if my date has an assault conviction. Just because the police office is in a place where such information is readily accessible doesn't mean that they are allowed to just use it for whatever they want. As an IT/support tech, I have remote access and admin passwords to dozens of servers for dozens of companies. Only once have I ever used one of my clients' servers for personal use, and that was to demonstrate a particular piece of software for a friend of mine, with explicit consent of the owner of that server. LEOs don't sign up to be LEOs with the promise of a $250,000 salary and then realize it's between $40K and 70K a year. That information is abundantly clear long before they ever step foot in the police academy. Access to my confidential data is not penance for making less money than a doctor or lawyer. Even if you are okay with it (as is your right), I am not. The question is which one of us should be able to impose our feelings upon the other.
The second issue I have is with this part...
Put yourself in their shoes. [snip] You have no clue if he just murdered his girlfriend, has $5M in heroine in the trunk, is off his meds or is high out of his gourd.
Nope. But the foundation of everything LEOs are required to uphold is summed up in the following sentence: Innocent until proven guilty. Maybe he did just murder his girlfriend...but unless there's a dead body in the front seat, he didn't. Maybe he's got $5M of heroin in his trunk...but until there's probable cause to search the vehicle, he doesn't. Maybe he is indeed high...that will become bleeding obvious in about 30 seconds of interaction.
If he is not obeying orders and is putting his hands in places where a weapon might be concealed, you have a very reasonable fear for your life. So while not 100% of police shootings are justified, you are a sociopath if you can't at least empathize with the people in our society who put their lives in danger to protect us from the criminal element.
My level of empathy is strenuous at best, for two reasons. First, if the job is too hard, quit. It's not hard to stop being a police officer. There is no shame in saying, "being a competent police officer is too hard for me". It is a tough job, but the difficulties of that job are no secret. If someone signs up to be a police officer, they are signing up to carry a gun that they will hopefully never have to use, but are lawfully authorized to use far more liberally than the average citizen. With that authority should come accountability...and the perceived lack of said accountability is the root of the challenges at hand.