A flat planet (ours or any other planet) would be such an incredible observation that it would pretty much go against everything we know about how planets form and behave. It would not only change everything we know about planet formation, but also about star formation (our sun would have to behave quite differently to accommodate the flat-earth theory) and what we know of speeds and movements in space (like planets' orbits and the effects of gravity). In short, we don’t just suspect that our planet is spherical. We know it.
While it's true that unipolar magnets can't exist, this isn't a problem for the Flat Earth. This is because ring magnets, which are shaped like (you guessed it!) a flat disk, are capable of having radial magnetization. In a radial magnet, one magnetic pole is at the center and other is at all points on the edge of the magnet. A magnet like this can be found in loudspeakers, and perfectly replicates what is found on the Earth.

163) NASA and other space agencies have been caught time and again with air bubbles forming and floating off in their official “outer-space” footage. Astronauts have also been caught using scuba-space-gear, kicking their legs to move, and astronaut Luca Parmitano even almost drowned when water started filling up his helmet while allegedly on a “space-walk.” It is admitted that astronauts train for their “space-walks” in under-water training facilities like NASA’s “Neutral Buoyancy Lab,” but what is obvious from their “space bubbles,” and other blunders is that all official “space-walk” footage is also fake and filmed under-water.

92) The Notre Dame Antwerp spire stands 403 feet high from the foot of the tower with Strasburg measuring 468 feet above sea level. With the aid of a telescope, ships can be distinguished on the horizon and captains declare they can see the cathedral spire from an amazing 150 miles away. If the Earth were a globe, however, at that distance the spire should be an entire mile, 5,280 feet below the horizon!
9 And God said, Let the waters under the heaven be gathered together unto one place, and let the dry land appear: and it was so. 10 And God called the dry land Earth; and the gathering together of the waters called he Seas: and God saw that it was good. 11 And God said, Let the earth bring forth grass, the herb yielding seed, and the fruit tree yielding fruit after his kind, whose seed is in itself, upon the earth: and it was so. 12 And the earth brought forth grass, and herb yielding seed after his kind, and the tree yielding fruit, whose seed was in itself, after his kind: and God saw that it was good. 13 And the evening and the morning were the third day.
3) The natural physics of water is to find and maintain its level. If Earth were a giant spinning sphere tilting and hurling through space then truly flat, consistently level surfaces would not exist here. There would be a massive bulge of water in the oceans because of the curvature of the earth. If earth was curved and spinning the oceans of water would be flowing down to level and covering land. Some rivers would be impossibly flowing uphill. There would massive water chaos and flooding! What we would see and experience would be vastly different! But since Earth is in fact an extended flat plane, this fundamental physical property of fluids finding and remaining level is consistent with experience and common sense. The water remains flat because the earth is flat!