a) References appearing to the Airbus 'stall recovery pull-up' manouevre. Is this right?
As I (a non-pilot) understand it, there has been a commonly (A+B) accepted drill for "approach to stall recovery" which involves application of power and sometimes a pull-up to minimise altitude loss? Now both A & B are saying that this approach can lead to confusion and possible accidents if the aircraft actually gets into a state where the only possible recovery action is to push the nose down, reduce AoA and only then pull up. They are jointly recommending that this drill becomes standard even for approach to stall conditions.
No doubt if I have that wrong in any particular the flak will fly
b) References to the fact that the stall warning 'cannot' sound in Normal Law. Is this right?
"Cannot" is perhaps the wrong word - "will not" would be more accurate since the system in normal law is supposed to prevent any transgressions above alpha max. Consequently there is no audio stall warning associated with normal law.
c) References to situations where alpha floor protection in some species of Alt Law might be absent. Is this right?
Alpha floor depends on a functioning autothrottle - it is, so far as I know, not available in any of the alternate law manifestations.
BOAC, it seems to me, from the information I have available, that the audio warning of a stall* begins before the wing actually stalls, in terms of the AoA value that triggers the crickets? Since the crew can't see their AoA, they must rely on such a trigger to become aware of an impending stall.
(* = or warning of impending stall)
The audio warning is actually an "approach to stall" warning and is typically triggered a couple of degrees AoA below the actual stall. There is a subtle twist in that the trigger is modified by a 'rate of change of alpha' signal which is intended to give warning of a rapid approach to stall AoA. So far as I can judge, the stall warning would be triggered just above the AoA at which buffet becomes perceptible, but below that at which buffet is deemed to be intolerable.