I would think that none of the scenarios you listed would justify landing above the published max landing weight
I am sorry to say that, but you are quite mistaken. Here is an excerpt from our ops manual.
'...Overweight landings may be performed in all abnormal or emergency situations where according to the commanders discretion this course of action provides the same or a higher degree of safety than jettison fuel or continuation of flight.
Situations as serious illness of crew or other persons travelling on board which would require immediate medical attention also justify overweight landings...'
In doing so, you'd be risking structural damage possibly totalling a $100+ million aircraft.
Normal sink rate at touchdown averages 120 ft/min. Airplanes are usually certified with a sink rate of 360 ft/min at the structural limited TOW and with 600 ft/min at the maximum landing weight.
Structural problems will not arise, if sink rates at touchdown do not exceed 360 ft/min.