Dave, What you say seems on the money, but we cannot forget that this whole incident is about money and this will affect your item (c)
To recover their lost customers, UA will need to establish and publish a more client friendly bumping procedure. Otherwise they could be known for years as the "drag on, drag off" airline!
In court the ramping up of crew authority would possibly establish an increased level during pushback, more during taxiing and full authority at some point during the take-off roll. Original legislation might not have considered what a court might. Prior to crew boarding, as an example of the complexity, captain authority includes refusal to operate if aircraft is unserviceable, his fuel decision not met etc. In practice he simply makes his requirements known and his ultimate authority to refuse the flight forces company to treat his requests with a similar authority as would his crew and pax during flight.