Veronica, I think your 4/30 hoodlums was pretty much par for the course in every classroom I had! The way you described the other 26 made me cry. I guess inside, I will always be a teacher.
And I also read many things to my kids that were "on the edge" because I knew their parents didn't discuss anything important with them. I would preface it by saying,"maturity alert." And then I would tell them that since I was their teacher they would have to "get over it" and not be embarrassed by frank discussions of human relationships because this is how we learn stuff. I also would say that after having 2 sons, there wasn't anything that would shock me.
And yes, I think that mostly there is very little sense of community left, unless one intentionally sets out to build it. That is why we moved back east. I was getting more and more discouraged with the transient nature of the community in AZ. Not that I didn't have a great life, good job, nice house, friends, etc, but something always felt like it was missing. Now I know what.