Would the people of the Indian subcontinent have been better off if they had attained independence as one country, rather that two?
Many of the ethnic struggles and civil wars in former colonial areas can be traced to the fact that during the colonial period, European nations drew up territorial lines without regard to ethnicity, which often placed people with longstanding hostilities and other differences under the same governments. What is more, European powers usually privileged one ethnic group over the others, or even created ethnic differences through their policies (e.g. the Hutu and Tutsi in Rwanda). Once the European power left, the tensions exploded, because often the borders remained the same as during the colonial era. By dividing, India and Pakistan avoided this problem, to the extent that it was possible. So I don't think a unified subcontinent would have been a viable option.
I've never heard of Italy referred to as a subcontinent. If you are talking about India, I agree with the post above. Since the split was amongst cultural lines, it probably saved a lot of internal strife and dissension.
I don't think so. I think that if they had become independent as one country, they would have ended up as two (or three as it is now) any way. The split of Pakistan and Bangladesh indicates to me that the various parts of the subcontinent were not really likely to stay together. Better to become independent as two than to have to split up.
Looking at the status of Muslim in general and the Muslims of Jammu & Kashmir in particular, partition was the only option.
The cultural differences can be envisaged looking at the fact the Muslims slaughter cows and take it as a delicious food whereas in Hindu religion a cow is given the status of a mother, more or less like a goddess. Cows' dung and urine is used by Hindus for purification whereas Muslims consider it to be filthy and have to wash it off their clothes if soiled with this filth before they can offer their five-times a day contact prayers etc.
It would have been impossible for them to live like a coherent nation. Many riots have taken place in India due to the Hindu intolerance for Muslims and demolished Babari Mosque in Ayodhya is one of such Hindu prejudice.