The P-47M rolled out of the factory as basically a D-25/D-30 (exactly like we have in game) with the same engine and horsepower as the P-47N. Other than some different systems in the cockpit and other miscellaneous changes, the airframe is identical to a bubble top D-25.
The P-47N rolls faster because the ailerons have much more authority than the ailerons on the D. The P-47N wing is larger than the D wing, with a span 32" wider, and roughly 30 more square feet. The ailerons make up the same percentage of wing area as on the D, so with the larger, wider wing, the ailerons are bigger and further from the fuselage, therefore having a higher moment in the roll axis.
It will not get "F4U4" gas mileage because the induction systems are different--F4U4 is supercharged only, while the P-47M/N is turbocharged. The P-47M will get P-47N gas mileage because its the same powerplant and configuration.