Could the universe have evolved WITHOUT the non-determinism of quantum mechanics? (I'm going to make a few conjectures here - please answer the question in light of them as if they were true, even though of course they may be overly simplistic or wrong)
Assuming that:


*

*the universe had a beginning, at a singular point in space 

*the net energy of the universe is zero

*all conservation laws and symmetries hold perfectly at the highest energy scales

*all fields are perfectly unified at the highest energy scales


Could the universe have evolved beyond this dimensionless singularity if the laws of physics were perfectly deterministic? Would such a system need an initial seed to break symmetries and begin evolving, and could it be given such a directed push in an entirely deterministic framework, if it started with no net energy and no particular bias (geometric or otherwise)? Is it meaningful to ask if the process had to be initiated by an element of randomness?
Sorry if the question is overly vague and superficial; my knowledge of physics is somewhat limited (at least compared to most of you kind folks).
[edit] I understand why the question was put on hold. Thanks all the same. :) If I think of a more appropriate way to recast the question I will submit a new one if it is sufficiently different to warrant it. 
 A: The question is very speculative :-) Physics is based on models out of our experience of a world extended in space and time together with mass and energy. One example: The concept of point is already a Euclidean idealisation. It lives in the world of mathematics - not of Physics (otherwise, you fall into Democritus and QM) Indeed, in Maths, we still struggle with how to make sense of such infinitesimal entities (e.g., hyperreals, surreals, Robinson's infinitesimals, etc.). Classical reasoning applies to ordinary world. A possible Universe beginning is not ordinary: require exotic thinking (unknown to me) :-)
A: Your question is really tricky. I am going to try to discuss two of the issues in the first two paragraphs. The rest of the paragraphs will speak only purely formally about how "old" classical cosmological equations would work in the case you describe and what a physically intuitive interpretation of the singularity could be.
First, without quantum mechanics, we do not really know how matter works, what an atom would be, how reactions turning different types of matter into each other can happen etc. etc. So for example your question would in a way imply there can be no reactions creating first protons, first hydrogen atoms, first atoms of Helium, not to mention any non-monoatomic chemical substances.
Second, when you say "the net energy of the universe is zero", this would mean there is also no matter (remember that from relativity we have matter$\sim$energy) nor radiation. This universe is empty and what you are looking at is a vacuum solution of the Einstein equations. Most importantly, there is nothing to form or change in time, so there is nothing interesting apart from the space-time itself.
But, if we just take a universe which is perfectly-homogeneously and perfectly-isotropically filled with perfectly-continuous matter and radiation (i.e. non-atomic) in equilibrium thus described completely by the FLRW metric, without quantum effects or inherent randomness, there is no reason for inhomogeneity or non-isotropy to grow. As a consequence of General relativity, this super-smooth universe gets either blown up or shrinks according to the Friedmann equations and the super-smooth matter and radiation diluted also accordingly. There are no stars, no galaxies, no planets, just a dull completely uniform background. On the other hand, even with presuming an isotropic and homogeneous universe with quantum effects "turned on" later, some kind of structure formation would always occur.
We cannot say what happens at the very singularity using General relativity just out of plain mathematical reasons. This could be compared to the situation when we cannot say what $1/0$ is, the mathematical form of the law just does not have any good meaning at that point. Nevertheless, for perfect GR range of applicability any point arbitrarily close to the initial singularity, the universe would keep expanding (near the Big Bang) or shrinking (near the Big Crunch) without any help of quantum principles. 
Far beyond the reach of any physical relevance of such a discussion, we could argue that no quantum principle is needed for the "start-up" of such a singularity - we could say it's behavior is always defined by the one-sided limit of the points of evolution taken closer and closer to it. But, this is really just an intuition of how a physicist would handle such a break-down of equations in a different context, there is really no rigorous approach.
