A United India under a majorithy Muslim government does not necessarily mean it would have faced the same challenged as Pakistan. Not at all.
In fact, I believe for a while the trajectory of the two countries was identical after partition. The leadership on both sides was elitist, post colonial but heavily influenced by colonial style leadership. Pakistan was small enough for them to control through the military. India on the other hand was too big, diverse with a number of differing thoughts and views to be able to united under one method of control as in the case of Pakistan. I would say with so many ethnicities, religions, languages, most of you guys never agreed on one thing and neither did your military or elitist leadership.
That is where the paths diverged, which is a good thing for India and bad for Pakistan. So, I would say, NO, a united India would not be going to the IMF with a begging bowl. The only reason Pakistan has to because the elitist establishment has stolen everything we had and did not put in any development plans.
It is a double edged sword though. We do not know if Muslims would have been in majority in India after 75 years of independence. It is very well possible that a majority Hindu India would have gone the route of MODIism in 1965 rather than after 2010 which would have possibly resulted in a genocide or at least conditions that would not have allowed Muslims to multiply so much as they have in Pakisan and Bangladesh. I guess we would never know.