I think the etiquette you descibed is proper for any river or stream in the world. The exception would be fishing the hatchery holes like Reiter on the Sky and Fortson on the Stilly.To expect to have first/only water at these places is silly.However, it is still courteous to ask before crowding in on someone at these holes.
The important thing is to never let some asshole ruin your day.Just find a different hole where you can do your own thing.