Yes the history with buddhism's wax & waning is interesting, I'd like to know more. Especially since it seems both high-class and low-class people were involved. I have the impression many were disappointed in how much conversion to Islam helped their status; it's not about what you claim to believe (like the christian/muslim concept of religion), it seems like what matters is what everyone else knows.
There were indeed lots of kingdoms, a whole continent's worth, but for the most part I didn't think the political units much influenced the rules of these things, aside from sometimes incentivising conversion to islam. I don't think there was anything like the european squabbles over who gets to be pope, or whether your country's church follows him, because there's no idea of centralised doctrinal command like that.
There were indeed lots of kingdoms, a whole continent's worth, but for the most part I didn't think the political units much influenced the rules of these things, aside from sometimes incentivising conversion to islam. I don't think there was anything like the european squabbles over who gets to be pope, or whether your country's church follows him, because there's no idea of centralised doctrinal command like that.