It sounds as though you are saying that local authorities cannot control airspace at all. But if that was the case, I would have expected the FAA participant to have indicated that FAA has sole control. His comment that forming relationships with local government and educating them [on the rules] avoids problems. That sort of implied to me that there were some things that local governments could do to restrict (delegated to them by FAA?).
That the FAA rules override seems to contradict several states (for example) that have banned the operation of drones in state parks. What am I missing here?
I'm wondering if this is sort of like the satellite dish situation where some homeowners associations have wording prohibiting use of these dishes, but the FCC is clear that no rules may be made to restrict the ability of a user to receive a signal using these. Thus the HOA rule is not enforceable.