Dave does try too hard to be cool and it comes off as being desparate, but here's my theory- from the guys' perspective, Dave poses little or no threat. Why? Because if it came down to Dave and one other guy, the chances are the girl will pick the other guy. Unless the girl is Charla, who may still be holding a grudge for how she was an outsider for the beginning.
So the guys should be scheming to get everyone except Dave off. Right? Knock off the handsome, funny, likeable guys so you (assuming you're the guy) would be left with a bunch of wannabes like Dave and the girls would almost naturally pick you. It's a sure bet.
Wouldn't that be the strategy? To take out the true contenders when you can so you'd win? Unless the "wannabes" would be the spoilers...