As to when and where you can fly, private pilots aren't regulated -- by that I mean, as long as you stay out of controlled airspace, you can take off and land and fly wherever you want without federal control, correct?
So, your intrastate activities are not regulated by the federal government. Only when those intrastate activities have a substantial effect on interstate commerce, does the FAA get involved.
I'm not a pilot, so excuse me if I oversimplified. But I hope you see the general point I'm trying to make.
Cite, please.