They play much more hardcore stuff, like Korn instead of All American Rejects.
Raven's the leader.
If Michael gets restless in daylight, he'll go ahead and climb against Raven and Raven would kiss his forehead and hold him as they slept.
Haven regularly buys stocks of medical blood from the black market. Just so they don't go around slaughtering everywhere they go.
All Vampires have the power to hear thoughts and send psychic signals to other vampires. If they're strong enough, their messages can cross continents.
Julian would want Raven for his music and power.
The first of Haven to get with Julian was Raven. It was almost like he was waiting for the opportunity by the way he was unstoppable to be first. After Raven managed to do it, the others (who weren't Clark, because Clark's had him before) seemed to take it as a signal that it was okay to try and see what he was like in bed.
Haven are probably one of the most well-fed vampires out there. They've got too much stock to draw from.