There was spare capacity in the UK. Resources for the development and production of the Tarus for example an engine that wasted a lot of effort. Production could have been passed on to Bristol with little disruption.
Hindsight, again, and do you really believe that R-R would have acquiesced with a competitor being asked to build an engine they saw as useless?
The engine didn't need any alterations to use 100 octane. It did need changes to make use of the extra potential offered by 100 octane and the use of 87 octane in fighter command wasn't a problem anyway as ALL RAF stations had 87 octane available as well as 100 octane.
That flies in the face of what R-R said; do you have any evidence, whatsoever, that they lied?
I notice that you didn't comment on my observation that the Whirlwind have a higher performance, that when the Luftwaffe arrived in the desert the Hurricane was outclassed and that the JAAF had a clear advantage over the Hurricane.
Mainly because I fail to see how events of 1941/42 have any relevance to decisions taken in 1940; you can apply 2015 knowledge to criticise what was done/not done in 1940, but the authorities didn't have that sort of information, and I don't believe that they had access to soothsayers.
And regretted it as it was too specialised. See attached letter
I note that you omit to mention that the Hurricane IV had the "universal wing," which allowed it to carry the 40mm cannon as an extra option.
As mentioned before there were a number of designs that were continued with that would have provided the extra resources.
Yet again, you're relying on hindsight; decisions could not be made in 1940, against information yet to be discovered.
Simply wrong. Fighter command were desperate to get the Whirlwind into combat during the BOB and the squadron leader refused as it hadn't reached the right level of reliability.
Doesn't sound as if F.C. were desperate to get the aircraft into service (last two sentences, first paragraph):-
27-10-40, Dowding wrote that he'd had a report from 263's C.O., which contained the following:-
"There is no tendency for the aircraft to spin in tight turns, but at heights above 26,000 feet the performance falls off rapidly and it is difficult to maintain height.
It must be emphasised, nevertheless, that the performance of the Whirlwind above 20,000 feet falls off rapidly, and it is considered that above 25,000 feet its fighting qualities are very poor. The maximum height so far attained is 27,000 feet but on every occasion that a height test has been carried out there has been a minor defect, either in airscrew revolutions or in lack of boost pressure. It appears possible, therefore, that the Whirlwind will in fact, under favourable conditions, attain a height of 30,000 feet, although the last four or five thousand feet of climb will take a very long time to carry out; the rate of climb dropping at this altitude to no more than 500 feet a minute."
To me, that does not sound like a ringing endorsement, and Dowding followed it with:-
"It therefore seems to me quite wrong to introduce at the present time a type of fighter whose effective ceiling is 25,000 feet."
7-11-40, Petter reported on a visit he'd made to 263 Squadron at Drem, where he found that they still had only 8 aircraft (so were still non-operational,) of which only two were serviceable.