Bouncing off your post.
1. Both passengers were booked to Bejing, and then on to Amsterdam. From Amsterdam, one was then booked to Copenhagen and the other to Franfurt.
2. In order to fly into China without a visa, one must have a pre booked flight leaving China from the same airport as the arrival set to leave within 72 hours of the arrival in China. With false documentation, it would have been impossible to obtain a visa to China, so they had to have arranged flights out to a Western country.
3. There was a previous bombing, more than a couple of years ago, on an African (?h airliner, where two people were given explosives and tickets that had three total legs, like this one did (A: Malaysia-China, B: China-Amsterdam, C: Amsterdam to X). The carriers were told to disembark from the flight at destination B and that the bomb would detonate on Leg C, but in actuality, it was set to detonate on the first leg and kill the unsuspecting carriers.
4. The consensus of opinion on the aviation forums I have read is that the likelihood that these two travelers were terrorists is pretty low, although not to be discounted.
5. One obvious problem with flying to a western country on a stolen passport is that you will be caught when you try to cross into the final destination as the Europena countries all do check the passport lists. So it is likely that the two passengers either were not planning on completing their journey, or were trying to illegally cross into Europe as refugees. To do this, apparently one would ditch any paperwork regarding citizenship so that there is no way for a country to easily "send you back where you came from", since no country will take you without proper paperwork. It has been fairly common for Syrians and others to use this method, and Thailand is considered a hotspot for obtaining stolen passports.
Ok, these are all things I have assimilated from reading outside of WS. I apologize for the lack of links, just consider it my opinion... Hope it adds some value.
Oh, one last thing, the story about the airline pilot contacting the plane after it had lost contact and getting muttering and static has been debunked. Several times.