Farmers mastered irrigation early, providing more crops than they needed to support the population.
Because the were being persecuted, and they believed that it was Zion.
An example of separation of power is having different branches of government that perform different duties, for example the legislative, executive, and judicial branch. Instead of having government concentrated into the power of one person
Spain and France were also among the strongest in Europe, with Portugal being a player early on because of their sea worthiness and exploration. I can’t recall of Portugal’s decline had already started by the beginning of the 17th Century, but it was getting close.
It would depend on the person. If a person doesn't have much it could be as little as a suit case and some money, or as much as a moving van and a car packed full of clothes.