I have a couple of minor issues with your theory:
1) Do we actually know there were marital problems and do we know the whereabouts of the wife and children. I’ve yet to see any reporting that indicates they are talking with authorities. Could they have left the home and skipped the country to reunite with the husband later?
2) There is no point in disabling the tracking systems if your intention is to drive the plane into the ocean. In fact there’s no reason to do anything other than overpower the co-pilot (this is assuming he’s not in on it) and drive the plane in the sea.
3) If this was meant to cause embarrassment to the Malaysian government, the bigger embarrassment would be to actually hijack the plane and turn it over to people who will actively work against the Malaysian government.
This sounds more like pre-planned plot to steal the plane to cause a problem for the government.
1) No information on the wife and kids, they are not at the house.
2)The point is complete evasion and disappearance. Why??
If there is no legal basis for charging the captain with piracy or any other crime because the blackboxes are not found.....the divorcing wife and kids can collect his life insurance.....
3)He is a lone wolf and they don’t play well with others because they are obsessed with absolute control of the operation.