All three of these Jewish groups began in the Middle East, according to the map provided. You can see that they originate from areas near Egypt and Arabia. But over time, the Jews spread to different parts of the world such as the Roman Jews going to Italy whilst the Exile going to Mesopotamia and Egypt.
Unfortunately, I can't answer that last question as I don't know much information about the Torah or what role it played during that time period. I hope this helps you someway regardless! Good luck! :)
That they were done on slavery and that they believed in equal rights for all
This combination or a mix of people could lead to confrontations or even wars due to their differences which might be based on hatred, intolerance and opposite beliefs. On the other hand, culture might be threatened, they would result lost because of the combination.
Difficulties to communicate because of the different languages people use.