Although I don't like your reasons, I'll let you have them. However, seeing as how apologetics has become a hobby of mine, I will have to correct you when it comes to the bible.

They had no word for "spherical", the closest word they had indicates a "pile".

As far as you claiming that the "four corners" proves anything, I'll ask if you then run outside trying to spot a good pet to take for your own when someone tells you its raining cats and dogs.

Besides, you can't have it both ways. The law of non-contradict dictates that the earth can't be circular and have corners in the first place.

That's just a general answer.