Okay, if anything was truly fake, it was the fact that suburbanites, in their early 20s, were hanging out a liquor store. You outgrow the Quick Stop at like 15 (as soon as someone gets a car...)
And, of course some of the dialogue is not belivable. However, what film is immune to this? Real life mobsters talk about how certain things in Goodfellas never would have been said.
But, the overall lineup of characters is dead on point for early 20 somethings in the mid '90s, in working class/middle class suburb. And, allthough Steve Zahn's character was over the top, he was indeed realistic. Everyone between the ages of 25 and 35 that grew up in the lower middle knows someone just like that. Truthfully, what was over the top about him is that even though he was realistic, he was probably even more funny than the real life, happy go lucky stoner we all knew growing up.
To agree with you, the only character that probably was a little bit fake was the girl with the punk hairdo. Any girl who looked like that was probably more quiet, and less opinionated and spunky. In fact, if you take the girl who overdosed and just switched characters with the punk one, this might have been one of the most realistic movies ever made about the American suburbs, sans, obviously, the rock star done good who comes back to town. In my neck of the woods, it was usually a baseball player. We had one that played for the Yanks, on the '96 world series team. (bench warmer..but stil..)And, when these pro baseball players would come back, they would only stick to a few friends they had, and they certainly wouldn't roll up to the guys hanging out at the convinience store. Also, Parker Posey's characer, the manager, was phony, too. For my money, she was just eye candy and an added, erotic twist to the storyline of the ex football player. Showbiz.
If anything, they were too whiny and too funny, but all in all their overall chemistry was certainly realistic, IMO. And, I'm 32, which made me 22 when this came out, and from the Suburbs. Wasn't the most popular guy, but I didnt miss out on anything. So, I'm as good an expert as anyone..lol.