I somewhat recognize this from my own background. Somewhat. I was kind (still am, I hope

), but I was not very silent. I am more careful when I speak nowadays, I think. I hope

.
I'd say, silence can weirdly enough seem threatening to some people, who may get the feeling that you ignore them. And in an attention-seeking environment it probably gets worse.
My own experience also tells me that kindness can weirdly enough provoke some people; my guess is those people who get provoked by kindness have troubles with their self-esteem/self-respect - they may feel inferior/bad when somebody else shows kindness. It's weird, I don't claim I understand it

.
Regarding violence, I am of the opinion that general aggression is bad, and physical aggression should
never be accepted. I see three good ways of dealing with aggression:
* Learning to spot dangers and dangerous people ("
streetwisdom"), in order to avoid them altogether
* Learning some basic self-defense + train your running if you ever need to flee
* Use the rules, law and report to authorities if needed
Good friends are worth very much!
There is another thing I'd like to mention, something I've noticed in my own experience. A troublesome person may become less troublesome if you meet and talk to him/her in private (that is, when they are alone) and if you do it face-to-face (this is to counteract peer pressure from his/her peers); if you give him/her some respect and attention, and maybe find a common interest, you may end up receiving respect and attention from the troublesome person. If the troublesome person is a dominant one in the group, his/her new view of you may spread in the group. I've had success with this.
Note though, I am also of the opinion that some people just don't seem to get along together - but there are always ways to handle it. I am also of the opinion that some groups of people (e.g. groups with destructive behavior) should be avoided altogether.
Note though, all I speak of is from my own experience - I don't claim to be an expert on this.