I agree that the Americans and Japanese focused on longer range fighters.
However the US never used it's initial long range fighters in combat. Or used very few of them. By the time the US actually got into the war the need for protection, at least in US eyes, trumped the need for range.
P-38 went from 400 gallons internal unprotected to 300 gallons protected. went back to 410 gallons on the P-38J
P-39 went from 200 gal on the prototype ( maybe?) to 170 gals in the YP-39 and P-39C but capacity fell to 120 gallons with the self sealing tanks.
P-40 went from 180 gal to 160gal in the P-40B to 148 gal in the P-40E as better protected tanks were fitted, later P-40s got slightly increased internal capacity although like the P-39, some models had rather restricted capacity in an effort to improve performance. (120 gals on some L's and N's)
Early F4F-3 and -3As had 160 gallons in unprotected tanks, this dropped to 147 gallons with the initial protected tanks and then to 144 gallons with the F4F-4. FM-2s had even less.
The older P-36 could hold 160-163 gallons but performance figures are usually for 105 gallons with the 58 gallon tank behind the pilot being an overload ferry tank.
All interesting, and fuel capacity is at least one way to try to estimate a baseline for range, but it's probably at least as limited as the USAAF method of levitating to a specific altitude and then measuring the resulting distance. Other factors you and I have mentioned or discussed before already include drag, engine RPM settings, engine critical altitude, and wing efficiency, and in addition to that there are also propeller type and settings and probably other "intangibles". In many cases, the effective range depended on how the aircraft was operated.
One of the best examples of this was with the P-38. Obviously with the high performance turbo-supercharged engine it could be quite the fuel hog. Even with the 400 gallon fuel capacity P-38s still needed to reach far across the Pacific to attack their targets (and to escort bombers). But they were struggling. Enter Charles Lindbergh. In July 1944, Lindbergh, who was something of an aviation genius albeit with some questionable political ideology,
made a semi-legal visit to USAAF units in the Pacific, and began flying missions with the 475th Fighter squadron in New Guinea. At the time the P-38 had a flight endurance of 6-8 hours (depending how much high throttle was used) and a combat radius of 300 miles. Crew chiefs noticed that Lindbergh always had much more fuel than the other pilots when they returned. After some investigation and discussion Lindbergh's tweaks increased this to 8-10 hours and 500-600 miles. His method was simple in retrospect: reduce the standard 2,200 rpm to 1,600, set fuel mixtures to "auto-lean," and slightly increase manifold pressures. Conventional wisdom said this would cause detonation but it didn't. And this did not reduce cruise speed incidentally.
Similarly, mere fuel capacity apparently doesn't tell us the whole story with the various single-engined fighters. Though it only had 28 more gallons of fuel, the F4F-3 had a range of 860 miles and a combat radius of about 275 miles (without drop tanks), whereas the P-39D had a range of 390 miles (clean) and a radius of about 120 miles. Hence the constant complaints by US and Allied commanders about the viability of the aircraft. Drop tanks increased basic range to 600 - 700 miles (depending on who you believe), but the aircraft was still considered too short legged to be of much use as an escort or for example as a fighter bomber. I really don't know why the difference was so wide but I would guess that the Wildcat had a more efficient and certainly larger wing.
The P-40 fell somewhere in between with a range of 650 miles and a radius of 250 miles (or 200 miles for the P-40L). With drop tanks and an optimized flying regime they could make 850 miles range and roughly a 400 mile radius with a P-40e in the Pacific.
Of the three, only the P-38 came close to the combat radius of the A6M (up to 600 miles with the external tank), and only with the tweaks from Lindbergh. But both the Wildcat and the P-40 had considerably better range than most of the European or Russian fighters.
However for context the US Army specification that lead to the B-26 bomber called for ".... a bombload of 3000 pounds was to be carried over a range of 2000 miles at a top speed of over 300 mph and at a service ceiling exceeding 20,000 feet." Now the B-26 as built didn't come close to that desired range but shows the difficulty any designer of a hypothetical escort fighter would have been up against. The US army was asking for 2000 mile range medium bombers and even longer range heavy bombers in 1939.
The Marauder was also required to carry a couple of tons of guns and ammunition. The more lightly armed Martin Maryland II (updated from French to British standards) had a range of
about 1,200 -1,300 miles with armor and could make over 310 mph. And of course the early war B-17, originally designed to patrol the Coasts of the United States, also had quite a good range too. So it did make sense to have some long legged fighters.
It may have been stronger than many people give it credit for, and it may have stood up fairly well with good pilots. But that does not mean it was as strong as US or other western aircraft. There are two reasons for limiting dive speeds, 1 is the plane has control difficulties at high speeds. the 2nd is that parts start falling off the aircraft. They increased the dive speed of the Zero twice during it's career. If the early all metal Zero was limited to about the same dive speed as the fabric covered wing Hurricane what was the reason if it wasn't strength?
Sometimes the issue with dive speed limiations is construction strength so to speak (arguably this was the case with some of the Russian fighters), sometimes it's more the shape and size. One thing the early Zero (A6M2) and Hurricane had in common was big wings. The A6M2 had a span of 39' 4". The Hurricane had a span of 40'. I think that had something to do with speed limitations, as the later marks of the zero had shorter wings, the A6M5 had a 36' span.
Not that wing span alone would account for speed limitations or problems at higher speeds but I don't think either the Zero or the Hurricane were designed with such high speeds in mind (so much faster than the engine could take them in level flight), or the problems which came with it, whereas later fighters were designed to deal with such problems. On the P-40 and some other aircraft, I think they just lucked out with wing designs which worked well at higher speeds. And high speed in a dive turned out to matter a lot for escape.
I'm not sure what the dive speed limitation was for the F4F.
In some cases you may be right however some nations were a tight spot with less than first class engines (France and Italy) and Britain had the double whammy of believing that monoplanes were a passing American fad and variable pitch propellers were the work of Satan.

or at least believing on fighters that the increase in performance of the change in pitch would be canceled out by the increased weight of pitch change mechanism.
I could be wrong but I think France was well on their way to making some quite powerful variants of the old HS 12Y engine. No telling how they would have worked out of course. And needless to say, every nationality had their blind spots in terms of predicting what the machines of war would actually need.
If a country believed that a long range single seat, single engine fighter would be out performed (think out maneuvered rather than speed or climb) by the enemy short range interceptor with like power than perhaps building a long range twin engine fighter that could boom and zoom (although not using that phrase) instead of maneuver was a viable alternative.
Without a doubt. The problem in that case basically came down to making a two seat fighter that took advantage of it's larger size to achieve greater range, which the Bf 110 basically didn't manage to do very well, and which was faster than the single seat types, which it was up to the Battle of France but fell behind on by the BoB, and never caught up.