We have rules and etiquette we follow as part of the airsoft community. One of those big rules is to never shoot animals with our guns for ANY reason. People? Yeah. We make the choice that when we game, part of it is to get shot. For the most part, we're well protected with vests, goggles, etc. We make that choice and accept its consequences, which is something that animals - pests or not - can't make. I agree that it's better to shoot them with a 'harmless' airsoft gun than blow them away with a real gun, but still. You can potentially seriously injure a small animal with a high power airsoft gun. And that's something the community is strongly against.
As for the legalities of things, if you read the forum stickies, the answers are all there already in painstaking detail. Which is what I mean about reading more and posting less. The legalities of airsoft are complicated and it really lives in a grey area of the law. While ownership is not outright illegal, it's not outright legal at the moment either. However, there are holes in the law that allow us to practice our sport unbothered by authorities.
You'll find that asking about it in the forums will get you mixed answers, as many of the people chiming in don't really have a clear understanding of things either, and it turns into a case of the blind leading the blind. You'll get a lot of incorrect answers. The best it to simply read the accurate info that's been posted by forum admins on the subject and pinned to make them easy to find. Chances are, if you have a question about legalities, it's covered in detail already with accurate info.
And it's not getting "high and mighty". Your second thread you started, you outright announced that you intended to use your AEG for an activity that is illegal and that the community is strongly against. As age verifiers, we won't verify someone who has intentions to use their guns for illegal activities. We're a self-regulating community, and that's the mechanism we have in place to prevent our 'tools' from getting into the hands of minors, or adults that will misuse them according to community rules.
By limiting access to these replicas, there are less incidents that reflect badly upon our sport and could open the entire community to stronger enforcement of the law. To you, this may not matter as your guns are wall hangers that you plink with occasionally. Having a nation-wide crackdown on replicas because of an 'incident' won't affect you. It would have a profound effect on people that actually use the guns to play the sport. To you, these rules may seem overly harsh and unfair. But to us, they're in place to protect the sport we love and to ensure its continuity and longevity.