Jeremy,

The camp is not "atheists only", anyone is welcome to come. Plenty of the kids self-identify as agnostic, humanist or freethinkers. Kids of Christians are welcome, although they might not like how their kids come back - full of questions. The kids at camp quest find it hugely encouraging to know that they arent the only ones - it builds a sort of community which is freely available to the religious (eg church gatherings).

I'll explain about the unicorns challenge. It isn't trivialising the matter at all. The counsellors at CQ all have "faith" in these invisible unicorns. The kids are challenged to "disprove" their existence. But year after year, they can't do it (the original prize still stands). Transfer this to talking about god(s), and it teaches them a valuable lesson that it is practically impossible to disprove that which relies on faith alone.

No one is being a dick about it, least of all Dawkins. It's an extremely tolerant atmosphere.