Q. If India and Pakistan were not partitioned, what changes and Development would have been made till 2016?
Difficult to answer.
If the current attitude of Indian government towards Kashmir is a clue, then we are better off being partitioned. The cost of managing the partition is far less compared to holocaust of living with those who believe hate is their religious duty.
But if we would have taken proactive steps to eliminate all who hate non-believers to Hell for their belief-system, then India would have been super power by now. Since inception of human civilization, India was one entity. Regardless of political system, Bharat was Bharat or Arya Varta or Hindusthan or Barre Sageer or whatever you call.
We foolishly partitioned what was a divine gift of creator of earth because of our utopian notions of peace with terrorists and tendency to feed crocodiles. We spend so heavily in maintaining the border. And even more heavily because we are not able to maintain it properly to control infiltration. And minorities in Pakistan and Bangladesh suffer due to this stupidity of our forefathers.
It is time to create social awakening and create consensus among public of Pakistan and Bangladesh to reject religion based dogmas and stand for unification with India, like it happened in Germany. The era of blasphemy in our neighboring countries must end, and India must use digital and other mediums to influence this.