What alternative methods are there for controlling a plane when flight control surfaces have failed? I saw a TV show once about Japan Airlines flight 123, in which the aft pressure bulkhead ruptured, disabling hydraulics and ripping off the vertical stabiliser. So the flight crashed after some time of flying with up-and-down oscillation.

Since then, I've also heard of two flights in which the aircraft lost control of flight control surfaces, but pilots guided their crippled plane into a landing using engine throttles only:


United Airlines flight 232
2003 Baghdad DHL attempted shootdown incident, in which a cargo plane in Iraq was hit on a wing by a missile


In principle, could such a method have been used in Japan Airlines flight 123?

In principle, would it be possible to control such a plane by use of cooperating passengers moving around in the cabin, e.g. by instruction of a pilot, to shift the weight balance of the aircraft?
As far as I understand, the JAL123 pilots did use thrust manipulation in an attempt to control their crippled aircraft -- however, Japan's largely mountainous terrain conspired against them, as trying to figure out fly-by-thrust-lever requires a massive quantity of airspace, and unfortunately for JAL123, there was a mountain in the way of that effort.  UAL232 and OO-DLL, on the other hand, both happened over relatively flat terrain, which meant that the aircrews could concentrate on working with their crippled airplanes to get them back on the ground as safely as possible, without having to worry about terrain clearance.

Of course, the missing vertical stab didn't help them either, as it meant they had to do much more work to control their airplane.