Just saying, a lot of people tend to underestimate how much racism influences people's actions. Here's a quick test, what do you think the guy in the picture I attached does for a living? Stop reading and make a guess.
He's a Professor of Computer Science at Harvard. Definitely not what you had in mind, right? Now here's another guy dressed similarly:
Easier to believe, right? He has the exact same job.
It's little things like this that add up. There's a high chance that Chauvin saw him and instantly thought "here's another black thug, I gotta use maximum force on him blah blah blah". But the fact is, while he did have a shady past, he was actively working to better his community and was definitely turning his life around. Racism doesn't just include calling someone the N-word, there are plenty of micro aggressions black people face daily, and some of them snowball into things like the George Floyd situation.
Think about it, when you see a black person with a gun, what's your first thought? A criminal, maybe?
Compare that to white men posting pictures of themselves with guns, which most people just dismiss as them being "gun enthusiasts/gun rights activist".
People in the police force have these same biases and it leads to black people disproportionately being victims of police brutality.
Derek Chauvin was definitely a racist in addition to the other things you listed.