1.) Explain the movement of stars on your flat earth model. Why can't I see Polaris from the Southern Hemisphere. If you're gonna point to light refraction you better back it up with evidence.
2.)Why does Venus and Mercury transit the sun? How is that possible on a flat earth model? It must mean Venus and mercury are closer to the earth than the sun. hmmm
3.)How do you explain the seismic shadow zones which result from an earthquake? The way they are spread out is only possible on a spherical Earth
4.)What about the Coriolis effect? How can forces be such greatly influenced with such consistency on a stationary flat disk? The only explanation is the rotation of the earth.
5.) Why is it that when the sun when filtered (showing the true size) stays the same size throughout the day from sunrise to sunset? This doesn't work on your flat model.