The idea that people used to think that the world was flat is actually a modern misconception and "with extraordinary few exceptions no educated person in the history of Western Civilization from the third century B.C. onward believed that the Earth was flat".
#24 - LOL!! what?!.... I did not know that one. Great picture for it too.
#10 You would never get to the "other side". Where is Earth's center of gravity?
#15 Why would light travel AROUND the Earth? The Earth gravity is not strong enough to make light travel around. Maybe it's hypothetical "travel around"?
#20 Yes, because Sun is not an empty space. You can learn about this from "The Feynman Lectures on Physics".