1. It was a slogan that was aimed at a reform. The people shouting "abolish the police" and "defund the police" were not just making noise. They were absolutely advocating for what they were shouting.
2. There were 922 police officers in Minneapolis in 2019. That number plummeted to the 500s after Floyd and the associated unrest. The city council members, through their rhetoric, pushed out nearly a third of the department.
3. The best data I can find about that is here:
https://www.waspc.org/assets/Data Charts - Driving.pdf
I think it is common sense that telling criminals "if you run, we aren't going to make any effort to chase you" is essentially a "get out of jail free" card for anyone in a vehicle. Thankfully, as you mentioned, that reform was repealed.
4. Here's an article about what I was referring to in Atlanta:
Secoriea Turner's family sues Atlanta mayor, city leaders over fatal shooting. Essentially, armed vigilantes set up a barricade and the police were not allowed to do anything about it until one of those vigilantes shot and killed a little girl.
Also, some of these reforms were created through policy directives rather than legislation. For example, during the unrest in 2020 the police officers were I lived at the time were threatened with disciplinary actions if they made any arrests during the rioting. At one point officers were even fired upon and were forced to retreat with no arrests made. That was a major issue where I lived as people simply couldn't understand why the police were standing by and watching property damage occur. Several officers quit because of that night.