Those are exactly the questions on the minds of the Malaysian police as they--finally-- scrutinize the desktop computers (his laptop went with him to the cockpit) and the simulator in Captain Zaharie's house.
Perhaps we will never know what they found--but U.S. authorities involved in this search must demand these details.
Seems like a combination of three things may have caused him to snap:
1; One day before Flight 370, Zaharie was in the courtroom and witnessed the overturn of a succesful Appeal by his political hero for(allegedly trumped-up)charges of sodomy. Zaharie was outraged when he witnessed the Malaysian government-controlled High Court sentence said hero to 5 years in prison.
2; domestic problems coming to a boil with wife leaving Zaharie's house with his 3 kids
3; the approaching bankruptcy and closing down of Malaysian Airlines already brewing in his head.
Difficult to say just what Captain Zaharie had in mind when he took that outbound left turn, but suicide was not his intention--he rages to humiliate the present Government of Malaysia for ripping his beloved leader off the political chessboard.
And, By God, it's working!