I fail to see how FE theory "recreating the universe as Two Dimensional". This premise for "should we not be flat as well...should space time, not be flat?" makes no particular sense.
I also do not feel the need to define flat, as FE doesn't subscribe to it literally. Simply put, varying heights is easily observed but the Flat part of FE refers to the general, macro, shape of the Earth.
Although I do enjoy philosophy, I see this particular discussion to be fruitless. By all means elaborate, if you believe you can instill a destination.