Yeah, I'm sure some of it was much worse than what was shown in the movie. And like I said, who knows what the Eazy-E/manager stuff was actually like. Eazy-E is dead and I am willing to bet the manager is dead or wasn't involved in the project so most of it is speculation.
I don't necessarily think the cops were painted in the worst light. A lot of that shit DID go down (and still does). I don't have any issues with police brutality/abuse being called out in a movie like this.