A simulation scenario does not address the question of a beginning....who began the simulation, the creation of matter, the existence of time and space, etc. I'm not really a religious person, but when you look at the philosophical view from any basis, the questions are unanswerable...particularly from a scientific standpoint.
I understand your point, but I don't know how far we want to go into this matter on this forum. Part of the problem with the question of the "beginning" is that it makes a LOT of assumptions about time that aren't necessarily true. Human intuition and experience suggests that time is invariant, linear, and immutable, but in fact it is not. It can be mangled, created, and destroyed in the same way you can a magnetic field or similar, though doing so in any non-trivial manner is completely beyond our technological capability at the moment. Unfortunately, this doesn't answer the question, it just makes it more difficult to comprehend. Furthermore, the possibility of closed loops (which though they sound like it, do not have a chicken-egg paradox) is enough to make your head spin. It certainly fries MY brain. And then you have the problem that if even God exists outside our universe in proper God-like fashion, God still MUST exist within a greater System ad infinitum. It's enough to give you a brain aneurism if you really think about it.
I actually think the most logical way to think of God is as a being outside the scope of our universe. From our perspective, that is essentially the equivalent to omniscient and omnipotent, but not actually in the (impossible) mathematical sense. This perspective has the nicety of being both religiously and mathematically consistent, since the only context where it wouldn't apply is outside the scope of our reality.