In terms of carrying at the airport ...
I've been told that it's OK to carry in the non secure parts of the airport. There are signs up at the doors on DIA that say something to the effect that it's against Federal Law to bring a loaded weapon in to an airport, but it also says something about "unauthorized weapons" (should have written down the verbage). I think that with a CCL you're OK, but IANAL.
I haven't paid a lot of attention as I'm normally headed for an airplane so I can't have a loaded weapon anyway.