I Fly - seem to remember some pilot getting burned doing something similar to that. Did some low level stuff within the confines of the aerodrome (in the sad UK of course). Was prosecuted by somebody for low flying.
He argued that he was approaching an airfield and therefore entitled to fly below 500 feet. He lost the case when the Court agreed that the permission to fly below 500 feet over person, vehicle, vessel, structure was WHEN FLYING IN ACCORDANCE WITH NORMAL AVIATION PRACTICE - and doing his deliberate low level fly by/go around...and what you describe - was NOT (according to the Court) flying in accordance with normal aviation practice.
Before you growl at me - I agree with YOU. It should be allowed, for training purposes. But he lost the case.