Question is: If you had enough fuel and fly off of one end of the map... will you come back, after enough time has passed, and return on the other side of the map?

Well, that's a silly question. Everyone knows because the world is flat you'd fly off the edge into oblivion!!

(You see, we've actually tested this in AH - called EOW or edge-of-the-world tactics, another strange but true WW2 tale.).
And just in case people doubt the earth is flat, I have primary source charts to prove it:

