In Hinduism the sankracharya does not hold the significance that the Pope holds to Christianity. Also Hinduism is not an institutionalized religion as other western religions, therefore I do not think all of your arguments apply. Most of the time the comparison is made from the prism of Christianity and this does not work. It would be easier if one looks as Hinduism as a Civilizations where various religions and nonreligious systems flourish.
We have been influenced (or ruled) by foreign forces for over than a thousand years but rather then they changing us we have managed to absorb them. We are still what we were thousand(s) of years ago - the longest running civilization in the face of this earth(or Universe).
