Well, it seems to me that you are all completely missing the point. It wasn't doing run-ups on the move that killed them, or even the handling of the engine failure. What killed them was the attempted return to the field, followed by a loss of control as the airspeed decayed through Vmca.
In other words, a simple airmanship failure: FLY THE AIRCRAFT first, at all times.
There is no doubt in my mind that, had the pilot (whom one assumes knew the performance of his aircraft intimately) elected to continue ahead and put the aircraft down when it became obvious he couldn't maintain height, they could all have survived. There is enough flat, grassy land around GLA for that. It was the attempt to return that got them.
Most pilots feel an initial sense of anger or shame when they realise they have just made a big error, and this can cloud judgement. Most of us would want to be able to get the aircraft back to the runway if at all possible, but often you just have to accept that the safest option is to put it down straght ahead (+/- 30degrees). To my mind, that acceptance of an impending forced landing (never mind the ensuing investigation/paperwork/financial consequence), is one of the hardest obstacles to a successful outcome.
I never knew the pilot concerned here (although I had met him once or twice), but I am sure he was a great guy and a good operator. However, the very least that we should accept is that he made some bad decisions (however understandable), and people died as a result. There are many, many lessons to be learnt here.