1: A black dude is 2.5 times more likely to be killed as a white dude. However a black dude is also 2.5 times more likely to commit non leathal violent crime and IIRC 4 times as likely to commit actual lethal violent crime [MDK] which suggests that cops are just as likely to gun down a black man as a white man doing the same shit.Ife he was a black man being chased by a racist mob, the AG might see it as clear self defence but cops in the US don't have a good history when dealing with armed black men in high pressure situations.
2: Other than anidotal evidence in a country of about 350 million people for which one can find examples of just about anything, I doubt you have anything to actually back up your claim.
3: Considering point 1 and news coverage I wouldn't be suprised that the media underreports cops going MDK on armed white men which would lead to the impression you have. Tony Timpa was killed by cops who were joking and laughing after Tony called for help because he was off his meds and on other drugs. It didn't break local news. Same time period as George Floyd. But I guess cops killing someone in mental health distress if funny if he is white.
3b: Remember according to BLM silence and compliance so... but again he was white so that's OK>
Also considering the nature and reason for the riots it would be insane to assume the cops wouldn't hold back more with a black suspect than risk losing their jobs for doing their jobs. Remember that cop who shot that black chick, some even on terb were like brah even though she had a knife and was about to stab someone.