After many stubborn discussions some years ago Friedrich finally understood logistics and weather and realised that a German invasion across the Channel was utterly impossible.
However, I think that air superiority could have been achieved. Now, without the Spitfire in the scene it would have been a blood bath for the British even with a greater number of Hurricanes. Even if they could be much more easily repaired and produced, also they were much easier to shoot down by very experienced German pilots in supperb Me-109Es in 1940s. The loss of pilots would have been apawling and air superiority might have been achieved. But still an invasion...
Malta is a fine example. No Spitfires. No air superiority. Airborne invasion. No logistical chaos. A whole different outcome... BUT the problem of Malta is still not the 400 Spitfires available in November 1942. By May 1942 a German airborne invasion could have easily succeeded (and there were not enough Spitfires at that time to make it decisive).
And the far east is also a thing to think about. Japanese Zeros just swept the RAF away in early 1942 and the poor Hurricanes didn't even have a chance. The Spitfire quite contributed there if I'm not mistaken.
And I still believe that the P-51D was more substantial to the Allied air victory over the Reich in 1944. Without the Mustang the Luftwaffe could have kept a larger number of pilots and machines to keep the fighting going. Not to mention that without the P-51D the strategic bombing campaigns would have continued to have 1/3 loss rate, unbearable for the Allies.