"Q: "If the Earth was indeed a flat disc, wouldn't the whole planet crunch up into itself and eventually transform into a ball?"
A1: If the Earth generated a gravitational field, yes, it would eventually happen, after a billion years maybe. FE assumes that the Earth does not generate a gravitational field. What we know as 'gravity' is provided by the acceleration of the earth."
If the earth is accelerating, it is creating a gravitation field, which is why we are standing here right now, according to FE.
More precisely, the earth is warping space-time in a way that all of us are moving along the warps, as if going down a slide.
source: "The use of the term acceleration in conjunction with gravity arises from Einstein's principle of equivalence, which was a cornerstone in the development of the general theory of relativity. This principle states that the force produced by a gravitational field is qualitatively the same (in terms of how it affects physical objects, time, and space) as the force produced when a reference frame accelerates."
http://whatis.techtarget.com/definition/0,,sid9_gci804378,00.htmlSo, if the Earth is 4 billion years old, then wouldn't it have become a sphere?