We have no evidence of the bold part. Quaid was terminally ill and he left it to Pakistan constituent assembly to decide. Had he been the PM himself with mountbatten or any other gora as governor general, things might have been different and perhaps better for Pakistan as fascist hindus in india did the same. Our Quaid along with his ill equipped army was alone and surrounded by incompetent muslim leaders and disgustingly anti muslim hindus.
Anyways, now Pakistan needs a proper presidential system like US and Turkey, not the one with a dummy PM with president holding power. Head of state and govt should be the same, Turkey has done it and its better.
Allow me to disagree respectfully. What will change if Karachi becomes federal? Did FATA change, we had to merge it in KP. Did GB change? Is AJK doing well?
Karachi is in a turf war. Solution is actually changing the capital of sindh to a new coastal city and then having a local govt under mayor in Karachi. PPP knows that a urdu speaking will always become a mayor in Karachi so they never allow powers to go to Mayor despite a promise in 18th amendments. PPP will lose all sindh according to them. Hence the turf war.
If a new capital emerges, PPP will hold the sindh and they might be willing to give karachi local govts more powers. If we bring fed govt, turf war might even increase with rangers fighting all the time again.