You're so easy.
1. The flat earth theory spits on every scientist and great thinker you mentioned, with their theories and explanations.
2. The scientists and great thinkers you mentioned never questioned a round Earth. They provided evidence and working for models that would later be proven correct.
Irrelevant. They questioned the accepted knowledge of their day, something you are saying indicates weak-mindedness. How do you know that FET will not later be proven correct?
From memory, most of them just added to the knowledge of their time, or created an entirely new branch of Physics. You're right about Galileo, but he supported what he saw with a pretty little thing called 'empirical evidence'.
FET will never be proven correct, because (I love numbered arguments so much!)
1. It is not a unified theory. More of a 'most of us kinda believe the Earth is flat, some of us just believe it's not spherical, others think it's a finite infinite plane'.
2. It has nothing supporting it beyond terrible speculation, religious dogma and incorrect experiments.
3. It was believed once before, and then dropped for the Round Earth model, since everything tends to work with that model, even though it's somehow wrong.