Interesting that he operated the Vulture engines in direct contravention to the official procedure. It would seem that he didn't share his ideas with higher authority in order to extend others lives (never mind the engines!) as he did for his own crew. Was it because he would just be given a direct order to operate the engines as instructed? Rather reminiscent of Fighter Command's insistence on flying in tight vee formations, requiring total pilot concentration to do so rather than being free to sweep the skies for enemy aircraft. The cognoscenti soon learned to fly in a similar manner to their battle hardened opponents, leaving the more gullible as so much canon fodder. It seems that self preservation is a strong motivation in war. Yes, you do your duty of course, but with a determination to see that you can go on doing so for every subsequent day too!
It also seems that the Manchester had unreliable hydraulics as well as engines. Why should that be? Presumably it used the same components as other ME aircraft of the time; tanks, pumps, hoses, selectors, NRVs, actuators, etc. Why would it account for so many compromised missions as he lists? Icing, yes. The systems were prone to being overcome by heavy icing, no matter what the installed type was. Pulsating 'boots' that the enveloping ice simply ignored as it added more and more weight and disrupted the airflow, often bring the aircraft down out of control.