Eventually jinnah would have found that the politicians of pak were representatives of the landlords , mullahs and army and the common people had no real representative .....as he found at his deathbed, and so ,he would have had to take total control of the nation like a benevolent dictator in the fasion of ataturk in turkey.
Whether he would have succeded in taming the forces arrayed against him is a matter of debate.
It's difficult to comprehend what Pakistan or Jinnah would have become had the latter lived longer, just like it is difficult to say what would have been Gandhi's role in an independent India. Let' look at the two scenarios here
1. Jinnah would have been increasingly marginalised by the ruling elite, armed forces and the powers that be, because in their view he was no longer needed since Pakistan was formed. If not outright disrespect, he would have been forced to become a ceremonial head a la the emperor of Japan, while the powers vested elsewhere. Who knows some madman would have been instigated to assassinate Jinnah if was deemed too interfering.
2. Jinnah would have appropriated most power and decision making with himself (he did become an all powerful Governor General) and used that mould Pakistan into his vision- assuming he had one apart from getting Pakistan- bringing him into conflict with vested interests and leading either to scenario 1, or him becoming and all powerful dictator.
In either instance, India would have remained enemy number 1, to divert focus from the internal bickering, the rhetoric would have shifted to Indian bogey, whipping up hysteria and tensions in the region.
In my opinion, that's little different from the situation we see today. Jinnah's early demise allowed him to occupy the status of the revered "Quaid-E-Azam", whose so-called legacy, real and imagined has been used by successive governments to facilitate Pakistan's descent into chaos and degeneracy.