USACE regulations limit distance to public marina structures to 100 feet. That does not exclude any item in the marina property. It is not just the fuel docks, it is any marina structure.
Private and Resort docks are open to fishing by any boater. Respect falls under the rules of Sportsmanship, which means if you stick a lure in the boat dock, retrieve it. If you damage a canvas, vinyl or any item on the boat(s) or the personal property, then you should act accordingly and be responsible for those damages.