Jinnah - past to present

With the recent discussion, about the role of Jinnah in the partition of India, in different news papers. It interests me to know more about the partition. I would like divide my understanding in natural three phases; past, present and future.

We have learned for the classroom and other sources in India that Mr. Jinnah was responsible for the partition. But after undergoing different discussions, I understood that this was not the sole truth, few things are not clear to my mind.
1. How a single person be responsible for the partition of a nation.
2. When our congress leaders can fight for freedom with Britisher, why they can't made him (Jinnah) convinced.
3. How and why Mr. Jinnah change his mind during 1935 - 1940 ?
4. Was Muslim legue was true representative of Muslims ?
5. There might be many more factors contributing to the partition, what are those factors ??

Presently, India and Pakistan are two independent countries. My personal view is that they are not natural enemies. But in both the countries, it has been taught start from classroom that we (India and Pakistan) are prime enemies, what for reasons, no body knows ? Is being parted be the reason ? don't know. Before 1947, there was no Pakistan, and we were having the sole enemy i.e. Britishers, who were ruling our country.

Future - Unified India - Can we undone the partition ? can we role back the position to 1947 ? If it is understood in both the countries that partition was the major mistake of that time, can we correct that ? I know it is difficult but not impossible. There are instances in the history, where two countries became one, like Germany, but that require commitment from both the country men.

It might be very immature thought and need to analyse from various aspects of both the countries, but I know, I would be in benefit of both.

Arun