I dont have the energy right now to discuss the rest of the your post which would require me to fully apply my mind.
Here is a simple part though that I can discuss easily.
The fact is that a religious community does not need its own person to rule them is evident throughout India. But proving that does not mean that for a 100 years continuously some non-Hindu should run India.
Its simple, no one had an issue with MMS being a Sikh. The only reason he was voted out is because he has failed to run this country, rather run it aground.
People dont complain that Sonia Gandhi is a Christian. They complain that she is western and a foreigner whose loyalties dont lie with India.
If you think that Modi's election means Hindus are electing their kin to the PM post, then you could not be more wrong. The majority of the people voted for him because he promised 'ache din' with jobs, wages, faster GDP growth(its become like a drug to the people, cant live without it), good governance, less corruption. Why else would BJP have lost the election in 2004 or 2009 if all the Hindus were just bent on voting for Hindutva?
Otherwise even Rahul Gandhi is a Hindu.
The fact was that of the current set of leaders, Modi was by far the most competent leader. That is why people voted for him.
Or have you ever heard any Indian complain as to why Indian Army Chief is more often than not a Sikh?
Or have you ever heard an Indian complain that ex President Abdul Kalam was a Muslim? He is almost worshipped here as one of the greatest Indians ever and the best President India has ever had.
The point is that as long as every one is treated equally, no laws favour anyone - then all the people are happy.
Then it comes to competency..
Think about it, as a Muslim in US - you are allowed to not eat pork, you are allowed to not drink alcohol, you are allowed to pray to god as many times as you want. The Government simply does not interfere in your personal beliefs. You are free to choose.
Do you need a Muslim as the President of US to fulfill your needs?