If base reality is mental states and the perceived reality is an emergent illusion, there is no need for there to have been a Big Bang. It might explain some puzzles, such as why it appears to have been in such an improbably low-entropy state. Each individual's consciousness is generated traversing mental states that have increasing entropy in that realm but there need not be a singular low-entropy state.From the frame of the perceiver, the absence of perception is the absence of everything. It does not matter that the universe goes on without consciousness, or not. For the conscious perceiver, there is no passage of time, when consciousness ceases to perceive.
Considering that I am unaware of my state of being at the "Big Bang" (The beginning of the Universe, and the start of that first quantifiable moment), I can only know about the existence of time before me through a constructed/reconstructed model (i.e.: mathematics). My understanding of the vastness of the time since that first moment, tells me it is actually very quantifiable, even falsifiable, depending on our definition of the "beginning".
Logic tells me that that couldn't actually be the beginning of something so enormous, something so vast, so incomprehensible, as All Existence, so our mathematics is inadequate or our definitions, based upon some concept of the infinite, is misleading.
In all cases, the actual time in which existence has been, is just a flash, maybe not without dimension, but from a relative perspective, it can't be nearly so large as non-existence, except that non-existence is dimensionless.
For reincarnation, who to say that each incarnation of a life is time sequential, or even within the same universal framework?
Of those who believe in reincarnation, only a tiny handful claim to remember their past lives. Maybe they are right, but that only suggests that everyone has experienced a past life that happened in the past. Maybe, for most of us, our past existence has been in the future, another present loci, or in another universe completely, which could explain why we don't remember our past lives. The loss of sequence renders or memories null.
-Will
As I mentioned in an earlier post, Integrated information theory (IIT) posits that all systems in the physical universe (basal or emergent) might be said to have consciousness to some degree. I take the view that consciousness itself might be an illusion, just like free will, emerging from correlations across a path in a space that encodes informational states. The most probable path might well be one of minimal action, but there is no reason to believe that consciousness could not arise along any path that varies from this, although some might have very low probability. Perhaps phase cancellation can occur as in QED, but I haven't given that any thought.
As the basal realm encoding mental states is shared between all possible emergent consciousnesses, the threads of "selves" or "lives" are emergent from this. The probability Pr of retaining information from another thread, which you night term reincarnation, is perhaps the same probability distribution as that of information about shared events differing between threads: Pr = R.exp(-ΔN), where ΔN is the number of bits of information and the renormalisation constant R = 1- (1/e) ≈ 0.632. For more than a few bits, the probability Pr is extremely low. For 256 bits, Pr would be 4x10^-112. Even so, information might leak through sometimes.
If all possible "lives" are encoded as threads in a timeless realm, there is no death as such, but neither is there a goal or purpose.