In real world driving an M3 should be faster off the line then a 5-speed NSX because of the M3's fatter tourqe curve
Wrong. What matters to acceleration is not just torque, but TORQUE AT THE WHEELS, which is engine torque multiplied by the gearing. Even though the NSX torque figure isn't that high, it is offset by the fact that the NSX has a flat torque curve so that there's power WAY up to the 8000 rpm redline, whereas most other cars need to shift before that point. Once the M3 has to shift (at lower revs), its torque at the wheels drops because of the gearing disadvantage.
That, along with the horsepower advantage, is why the NSX is, indeed, faster than the M3 off the line.