I think I am learning about Pakistan through this forum. Since you happen to be born in Pakistan, your obsession towards religion is also understandable.
For your kind information, Delhi sultanate was destroyed and consolidated long long before British arrived on the scene. Delhi Mughal ruler was allowed to keep their privileges in return for sharing of tax revenues with Marathas. Here is the map that would illustrate you the control of Marathas just before British have arrived on the scene.
If Marathas, or for that matter all the kings and queens that ruled India would have changed the religion to Islam, that would have changed the fate of Pakistan as it stands today, right?
I feel like it is a lost cause to tell you that your religion obsession and glorious past if any has little significance on what is the reality today. If the poor in your country or mine has to survive, day dreaming and wishing does not help.
It seems to be a case like my grandfather had a fancy toy and I live like a beggar, and so if things would have different this way or if my father would have changed this decision, then the beggar's life would have been different thought the beggar - all the time still day dreaming whereas the beggar next door started doing some real work and progressing. Need I say which beggar seems like Pakistan and which beggar seems like India.
In a country where army is out competiting with TTP to prove who is more Muslim and hence has the right to rule Pakistan, your statements does make sense - a case of identity crisis.
When rest of the world including Muslim-dominated countries are concentrated on developing their countries, few that are left behind are obsessed on implementing Sharia law in their country.