Chugalug2,
You raise an interesting point about highlighting the risk of a loose object interfering with the control column on Airbus aircraft when the armrest is down and the seat motoring forward. I do believe that it is a difficult, but not impossible set of circumstances, not impossible because it has happened. Once. And that is once too often.
I think perhaps you haven't seen the geometry of the seat, the armrest and the control column, It takes some doing to wedge anything in there, it is difficult to do accidentally, although obviously it can be. Little has been said about what occurs when the control column is forced out of the 'detent' it is in when the autopilot is engaged and what happens when the autopilot is disengaged by moving the control column. If you had seen the geometry and heard the warnings then perhaps you could understand why any extra mitigation of the risk would not be as successful as you think and may possibly not have prevented this particular accident. There are enough very obvious clues as to what had happened and to was going on which this particular pilot didn't interpret correctly. Cognitive dissonance can be exacerbated by unfamiliarity with the environment and a lack of confidence in the system producing the warnings.