In a nutshell, a good example is what it takes to have a real gun range on your land. It's pretty much as complicated.
Remember that Joe Public only sees terrorists with machine guns, and that the laws and permits required have to cover that eventuality.
If you cant shoot machine guns, or even normal real guns, on your land, then you most likely cant shoot airsoft either.
I know, it's an extreme example, but it's pretty much true and the consequences you face are about the same.
The BEST thing you can do is to go play at local fields (or as local as possible) for a good year. Then you'll probably know what it takes and if it's worth it.