Yeah man I'm the same way, and don't want to come across as aggressive. I think on Twitter that's almost impossible lol.
Damn man, that story about trying to help your friend and getting beat for it reminds me of several times where I tried to help someone and regretted it lol. "No good deed goes unpunished" as they say.
By the way, I've also had that cop experience, well not nearly as severe. Had a cop one time with an accent, but spoke good English. He was either Spanish or Latin/South-American, and he was being overly aggressive and belligerent despite me being compliant, and trying to play along. I was with my girlfriend at the time, and we were trespassing so I was just trying to have everything go smooth for her. Almost like he was trying to be the bad-cop to the other guy's good cop. Eventually they let us go, but they tore my car apart as usual looking for contraband.

I had the long hair when I was younger. Still now it's probably long for a lot of people's "standards". But I mention it because I've seen the way people treat you differently based on appearance. Hair is a big one, but clothing/facial hair also play into it. The cops see a white guy with long hair and they assume you're holding something.
And that's nothing. I talk to older people about it, and a friend of my fathers told me a story about being bitten by rattle snake out in the middle of nowhere and calling 911. Sheriff shows up, and puts him in the back seat and drives around for hours without taking him to the hospital. He was letting him get sicker because he was a "dirty hippy" in the 70's. Eventually took him after driving the "scenic route".

Hey man, enjoy Florida. It's the free-est state in the nation, and it's got every type of American all in one place. Considering moving there eventually myself.