With regard to the actual punk show filmed yesterday: First, the mosh pit/crowd surfing bits seemed very real. I don't know how it will look on film, but it felt realistic. Second, I would listen to the main character's band's song in real life. Which is good because I heard it 3874 times yesterday. It's maybe not quite pop punk, but it's a lot closer to that end of the spectrum than it is to the hardcore end of the spectrum.
Going back to the wardrobe thing, I think the majority of punks I know don't actually dress that distinctively, and that's the part they don't get. I wear jeans and a band tee shirt every single day of my life. Take away the band tee shirt, and I'm just an aging hipster chick with weird hair. Show me someone wearing bondage pants and I'll show you someone who spent too much money at Hot Topic.