In fact by the time it arose, the aircraft may already have been in an unrecoverable dive (or whatever the word is for rapid descent while stalled), I don't remember. So it's not a primary cause of the accident.
There's no substitute for physical feedback. It's instantaneous and impossible to miss. It's completely beyond my comprehension that Airbus eliminated it.
As I recall, the one pilot held full back stick all the way down, while the other pilot tried and failed to recover. Releasing the back stick and executing a normal stall recovery would have saved the airplane at just about any time.
As for your last point, I'm not an expert, and I'm not as incredulous about this scenario as you seem to be. (As a teenager I did fly a lot in PC flight simulators, though.)
The non-technical Vanity Fair article I referred to claims that the accident investigators estimated the last point at which the aircraft could have recovered from the dive was around the time it passed 13,000 feet:
"Though precise modeling was never pursued, the investigators later estimated that this was the last moment, as the airplane dropped through 13,000 feet, when a recovery would theoretically have been possible. The maneuver would have required a perfect pilot to lower the nose at least 30 degrees below the horizon and dive into the descent, accepting a huge altitude loss in order to accelerate to a flying angle of attack, and then rounding out of the dive just above the waves, pulling up with sufficient vigor to keep from exceeding the airplane’s speed limit, yet not so violently as to cause a structural failure. There are perhaps a handful of pilots in the world who might have succeeded, but this Air France crew was not among them. There is an old truth in aviation that the reasons you get into trouble become the reasons you don’t get out of it."