No, he does not appear to have good sense. I imagine the exact location of that mooring is going to be variable!
What is an "approved mooring?" I don't think Maryland has a definition. Certainly a chunk of concrete can serve, just not THAT hunk.
Anytime we share the use of public property there is the potential for conflict. I don't think anyone on this board suggested you individually would stoop to vandalism, though some certainly promoted it. On the other hand, I think many have seen previously lovey anchorages ruined to for overnight use by the sprawl of private moorings and docks, and thus find themselves fundamentally unsympathetic to any assertion of exclusive right to use of a public resource. You can have your dock, but but don't expect a 200 foot buffer. Yes, I've had landowners bother me, that I have anchored too close to their dock for their comfort. I'm polite but unmoved. If I thought dragging was concern, I would be responsible for that. I don't like anchoring close to docks, but sometimes that's what is available, when the docks reach right out to the channel edge.