All through this tragic and appalling episode I have been most persuaded by the simplest solution - catastrophic malfunction, pilot tries to go back to KL, passes out and plane flies on in straight line until fuel runs out.
But I do wonder:
1 why Hashimmuddin is so evasive on background checks on crew. Maybe it is a "police matter" as he says but he is big shot enough to get the police to report, unless they have already done so and he doesn't like the answers. Ditto for the pilot's sim - seems not unreasonable to me that he should have one at home, so why not just go and take a look at what's there?
2 why no-one has said what's in the cargo - though to be fair, I'm not sure that anyone other than posters on this site has asked. The journalists certainly haven't at the last two news conferences.
3 what is the source of this notion of zig-zagging round the waypoints in the Andaman Sea and tracking the SQ flight? I can't find the original post, which might (very reasonably) have been deleted, I have only seen the comments which sound totally bizarre.