I can see the utility of this if the company is small (6 crews=12 people). This isn't your standard 9-5 job where you can sit in your cubicle/office and stay away from the people who annoy you. You have to be able to get along with the people who you will essentially be living with when on duty. I can see where there is a valid concern that one provider would ruin the kumbaya of the company. Similarly, no one wants to be that one guy (you know whom I'm talking about, just about every service has one) who no one wants to work with.
I don't view having a social and experience component as being mutually exclusive. I also don't get why they wouldn't ask for those things, even if they were optional.
Better question. If you wouldn't fit in with them, would you want to work there anyways? Are there other services that you can apply to?
I'm not familiar enough with privacy laws to say if it's a violation or not. Similarly, I can see why you would want to avoid companies that hire, in whole or in part, based on cliques. I don't see why, though, that would be an automatic disqualifies. I could argue that hiring based on the majority view of a good EMT (B, P, between) on this board, that it would be cliquish as well.