"You are overlooking the fact that Hitler never had any intention of invading the British Isles, and did not want war in the West. Britain should not have declared war on Germany in 1939, by doing so it destroyed itself economically and militarily and lost all of its empire."
Considering the fact that the US and UK were in a military keynesian economy at the time it may have actually boosted their economy instead of making it lag behind that of the SU.
"The UK and France should have remained neutral and allowed the Axis Powers a free hand against the Soviet Union."
Except that in the early stages of the war the Soviet Union was almost a literal ally of Nazi Germany. Stalin himself ordered that there would be no opposition against Hitler's regime by any who call themselves Stalinist. Besides, it's Hitler who wanted a war against France and the UK, and he got one.
"Nobody did more to destroy Britain's world status than Churchill, and this view is widely held today."
This is true, but it overlooks that Churchill was a racist and imperial colonialist that was just barely sane enough to not be convinced by Hitler's Nazi ideology (perhaps De Gaulle may have helped him realize how stupid "Mein Kampf" was).