My two cents:
-The last link in the chain is by tradition the "probable cause".Its the last link that made it inevitable.The door design introduced after 911 wasnt thought through properly.That Law of Unexpected Consequences again.Solve one problem but create another.
-This "two in the flightdeck" procedure might well create yet another problem down the road.They say act in haste,repent at leisure.I would say more thought needs to be given to the matter before jumping on the bandwagon.For me,the inability of the lawful commander to re-enter the flightdeck is as bad as having Mohammad Atta getting unlawful access to the flightdeck on 911.So that door is an unsatisfactory design.The authorities need to find a re-design of this DENY feature and they need it quick because this two in the flightdeck idea is a quick fix and a poor one at that.
-Talk of mental health problems is an insult to the 149 dead.Operating pilots cant have mental health problems.Death of spouse/divorce will depress even the most stable extrovert.Pilot takes time off.But chronic repetitive depression or bipolar?NO.Automatic disqualification.
-Although there have been several cases of pilot suicide-murder,it is very rare in the West.This case should not be used as justification to implement any Draconian measures that would make life anymore difficult than it already is for pilots.Lets not get caught by that Law of Unintended Consequences again.
-Pilotless airliners will happen.But they too will be victim of that very same law.