What are the cultural and societal influences that have made Hinduism vital to the region in which it originat

Answer 1

Hinduism as you call it is not areligion like christianity or islam. it has no founder. it is very ancient way of righteous living known as sanatana dharma. The computation of time was first done by the ancient sages which is followed by hindus even to this date.
great sages saints and kings were there in the ancient past who were far advanced in all the sciences. knowledge was over flowing and had reached the ultimate heights. Some substantial part of this knowledge is availble even today. It was taught that knowledge cannot be obtained just by casual study of any subject. Deep study and reserch was required and people spent their lifetime in researches.
The sages knew what is good for common man and accordingly the social rules were laid out.
The kings and the people respected the sages and took guidance from them in all matters. This practice is followed by most of the Hindus even today.
The observations of learned sages have always been correct.
to quote a small example;-
Astrology is a highly developed science and volumes and volumes of treatise are availble for guidance so much so that one astrologer cannot master all the portions even in a life time.
Even with all that very eminent Astrologers were and are there who could read a birth chart accurately like an elctronic engineer reading aprinted circuit.
The taste of truth keeps the Hindu's united despite all efforts to condemn their knowledge by half baked western scientists.