... much of this could have been foretold from the original A400M design spec with these big, turbo-prop engines....
What is wrong in principle with big turboprop engines? Please explain.
And even Lockheed Martin test pilots concede that the F-35 -- although offering very high initial acceleration due to its powerful 42,000-lb.-thrust F135 engine -- could start losing advantage at higher speed and altitude. This might be partly due to the aircraft's large frontal area, which is designed to allow internal weapons carriage --
That is contradictory and illogical. If drag due to large frontal area were a problem, the aircraft would be slow to accelerate at lower altitude. At higher, stratospheric altitude, flate plate or profile drag is less and less of a problem.
Furthermore, this alleged "large frontal area" may be providing more lift than drag. An aircraft such as the F-35 is a blended wing and lifting body design.
...meaning in a traditional quick-reaction intercept role, the F-35 may not be able to match rivals....
Which quick reaction role? Define that.
The F-35A, with an air-to-air mission takeoff weight of 49,540 lb., has a thrust-to-weight ratio of 0.85 ...
Your source for that ratio?
... and a wing loading of 110 lb. per sq. ft. -- not ideal for a dog-fighter.
You don't know what the F-35's wing loading really is. No, you can't calculate the wing loading of a blended wing and lifting body aircraft by taking the wingspan and chord and some guesstimated coefficient of lift and applying Oswalds's efficiency factor, and then dividing assumed weight by the effective lifting area you have erroneously and ineffectively calculated.
The wing loading is actually lower than 110lb./ft^2, because the F-35 gets significant lift from its central body, as I said above. Look, the F-35 is optimized for best performance below about 30,000 feet, as is its predecessor, the F-16. This means that the aircraft needs somewhat heavier wing loading for less drag in thicker, lower altitude air. Heavier wing loading is also needed to allow pull-up or turning maneuvers at high g rates in denser air, or else the wing roots and box structure will have to be made stronger and therefore heavier.
What do you think an F-16's wing loading is when configured for air to air combat? Would you say that the F-16 has not been ideal for a dogfighter during the past thirty years? Nobody's fighter plan is ideal for all altitudes and all missions
I'm not saying that the F-16's design is perfect. The F-16 has a pitch-up problem at certain airspeeds.
However, wing loading is something the designers of the F-16 and F-35 understood very well. The designers chose the wing loading for these two aircraft quite intentionally and for a good reason, which is that these two aircraft are optimized for flight at lower altitude. Nobody's fighter plane performs equally well at stratospheric as well as lower altitudes