Xavier, yes. I certainly don't blame him. All people react differently when dealing with fear and high stress situations, it's not their fault.
Oh, not saying it was. But it was somewhat amusing at the time. Only other issues I've run into with Forest Service was up in Prescott where we were told we couldn't park our vehicles where they were parked. But that wasn't a big deal either.
We have a very good rapport with the forest service in Prescott. It's not tough if you think rationally and just talk to them. Then everyone can stay nice and level-headed and have a great experience. We've actually gotten the forest service guys to shoot the guns and they generally have a pretty good time.
So... to answer the OP:
1. and 4.:
Echo everyone else... if you can shoot a real gun, you can play airsoft. Ranges are excluded from this generally... they don't like airsofters running around the shops. We play in the areas that don't get attention, because it's 100% legal to be there playing.
2. and 3.:
No bad experience with LEOs. Couple of sheriff visits and ranger patrols checking in after reports of large numbers of people with "automatic handguns". So... worst experience I guess is the rangers that pulled up as we were putting out a fire that was going when we got to our field... she seemed very concerned, but was happy to see us putting out a fire we didn't start.