The Incas were a very religious people; their religious beliefs were deeply embedded in their lives, everything they did had a religious meaning. They were tolerant of the beliefs of the people they conquered as long as they venerated Inca deities above all their gods, they even incorporated gods from other cultures.
Trade, travel, and transportation by boat..the natural harbors made it easy to navigate
In the time of 1980-1990 Poland, Eastern Germany, Hungary and others
were trying to get away from the authoritarian socialist systems imposed
on them by and controlled by the Soviet Union.
This was possible because Russia was undergoing changes political changes too. This was under the leadership of Gorbachev and if fact he received a Nobel peace Prize for this.
Depends on how you view him and what he did. I'm pretty sure you know he traveled the sea to find what we now know as the united states. Their goal was basically to find some gold for money but he didn't find any really. So it's really your opinion on how you think he did.