Abu Bakr was one of the people that Muslims considered to be the successor of Muhammad, the other one was Ali.
The split over who should be the successor, Abu Bakr or Ali lies behind today´s Shiia- Sunni split, where the Sunni believe it was Abu Bakr and Shia that it was Ali.
I think because no other country in the world has created something interesting or it was just a pass down by their ancestors and they wanted it to be a thing
1: It means that one government controls the whole population of people and the only way they can do that is to be voted in.
2: The best characteristics of a democraitc is that the rules for the country are direcly elected by the people. which means it is the government for the people by the people.
