Well if you insist, there's verses in Genesis and Job, water is always level, we can see the bottoms of buildings from miles away, and nasas fake astronauts are somehow able to re enter earths orbit
2. Yes, but to a certain extent as the horizon exists
3. Their rockets provide thrust in a way that allows them to re renter the atmosphere. From there, gravity does the important work
Now explain this, if earth is flat, then gravity at the edges will pull you toward the center. However at the edges of the earth gravity still pulls you downward