As long as the motor power stays under the ESC limits I believe an ESC swap won't make much difference. DIfferent story when one of the two ESCs is at the end of it's abilities.
A MMP can handle quite more than 65A, not only during bursts. I use one in my 4x4 Pede with a Castle 2650Kv motor in it. It never had problems feeding that. On 3S, that motor eats up to 2000W.
Motor torque is equivalent to it's power. If you have a 2 pole motor which has the same power as a 4 pole one, the torque will be the same.
Nobody is born with experience.