I'll do this one at a time. The incident lasted roughly 4 1/2 minutes. They had no visual reference to the horizon (IMC) and it was night time- these initial conditions made for a greater degree of difficulty in general. Their first mistake was in failing to avoid the weather by a wide enough margin. The second was in stall recovery. I can attest to the difficulty in recovering from stall in a heavy, swept wing aircraft at high altitude from my sim training. It takes patience and airspeed- the air is very thin. The less experienced pilot (PF) raised the nose at one point to beyond 10 degrees up which greatly reduced their energy state. Setting pitch attitude is distinctly complimented by vertical speed indications which were absent. Level pitch would be 2.5 degrees. He had total time of less than 3000 hours- low from my perspective but enough to be qualified.
the critical information relating to the flight situation of the aircraft was being withheld by the "smart" cockpit
The pilots were challenged by degraded systems: no air data meant they had no information about airspeed, vertical speed or altitude. It was attitude only during night IMC. No information was "withheld", per say, some simply wasn't available to them. They were all trained to standards, including stalls, and alternate law. Alternate law means that most protections are lost: pitch and roll limits, overspeed and stall prevention- you cannot stall newer Airbus in normal law, it won't let you. The aircraft still "flies" the same way. Boeing's cockpits are smart too, but are most definatley not immune to failures and connected yokes is not Here's a summary of Airbus flight control laws: http://www.airbusdriver.net/airbus_fltlaws.htm
If the former is true, what airline should I be flying on?
Like picking a surgeon or hospital, pick an airline that has quality training and experienced pilots. I would suspect that AirFrance has revisited their stall training for the better. Low pilot pay usually indicates low experience and poor training. High paid executives is a meaningless metric.
...the lack of any angle of attack gauge, a stall warning that does not sound when the airplane is so stalled as to be falling from the sky, and the lack of something making an enormous deal about the switch from normal law to alternative law flight mode.
Boeing doesn't present AOA either- it is not deemed relevant anymore with advanced flight display systems. Stall warnings (derived from AOA) are considered relevant and they did receive stall warnings: "At around 2 h 11 min 42, the Captain re-entered the cockpit. During the following seconds, all of the recorded speeds became invalid and the stall warning stopped, after having sounded continuously for 54 seconds." As for alternate law, I suspect your view of it is overly complicated. Direct law, however, is much like flying a paper airplane. The pilots will always be advised of what flight law the aircraft is operating in. Nonetheless, to get into that state requires multiple failures of redundant systems. With out any electrical power, the airplane cannot be flown- battery only is a greater emergency than fire.
Regarding the dual sticks with a dual input light, the key problem is this: when would averaging the joystick inputs actually be desirable?
Never. Its meant to be one stick at a time- just as pilots are trained on yokes. If the other pilot is fighting me on a yoke, I am the aural warning: 'I have the controls". In an Airbus the computer is the warning. We still must communicate on either plane.
Do both pilots frequently fly at the same time and average it out?
Never intentionally. That's why the system alerts them aurally and with a red warning light which can't be canceled and won't go away until the dual input is resolved. Few things trigger an aural voice: stall, TCAS, config warnings, and GPWS- all of which are "bad".
What happens when both pilots press the override button, do the inputs average again?
Last pressed gets priority. If one stick were to malfunction, holding the priority switch long enough latches priority.(i.e.until and unless the either button is pressed again). When priority is taken you hear "priority right (or left)", when locked out, red lights go away replaced by green. The AF447 pilots didn't fight each other on the controls the entire time: "At 2 h 11 min 37, the PNF said "controls to the left", took over priority without any callout and continued to handle the aeroplane. The PF almost immediately took back priority without any callout and continued piloting." This failure to communicate could happen on a Boeing. As the PNF didn't receive a "dual input" he knew he was not making an input at all.
Having direct physical feedback is more meaningful than a light somewhere else because it would be instantly recognized and impossible to ignore. Think, "you are touching the joystick, but it is vibrating, so you are accomplishing nothing."
It's good that your thinking like an engineer and a pilot. Studies have shown that people under stress "stop hearing" things, and they lose sense of time. I have no idea how much R&D went into the design, but I suspect it was given a lot more thought than you are giving Airbus credit for. Boeing has chosen a different design philosophy. Philosophically, neither is right or wrong, flawed or perfect.