I'm claiming that in this (such a) case, the singularity is the appropriate time/place to estimate the likelihood of the event from (as crazy as such an idea sounds).
Indeed it is crazy. It is absurd on its face, and we roundly reject it. Your proposal boils down to insisting that we base a computation on quantities that don't even theoretically exist, much less are practically obtainable. You provide no justification or rationale for this.
Rejected, but also see below.
Also, if determinism is true, the same implies. The figure we're looking for is the likelihood of your current existence 'before' the universal constants were established (if OOFLam is correct).
Meaningless twaddle. Again, you're suggesting something be computed explicitly without anything to compute it with or from, and that this is the only acceptable method. In a frantic attempt to distance yourself from Mt Ranier you're proposing that since the global basis of materialism is quantitatively intractable, no refutation from materialism should be considered valid. Quantification is
your bugaboo, not ours. Materialism doesn't require quantification in terms of probability in order to remain valid.
I'm claiming that for my question, that's the appropriate 'time' to figure from...
It isn't. It's an absurd suggested designed to bog the discussion down in the weeds, not propose an actual solution or method.
First, the result of this frantic handwaving doesn't change: both you and Mt Ranier are governed under materialism by long-running chaotic processes that don't lend themselves to quantification in probability. Pointing this out repeatedly doesn't help you.
Second, it's moot. The probability of any specimen arising via materialism is simply not an operative quantity or concept in the theory. Hence you need to heed jsfisher when he asks you to stay on topic. You're so deeply marinated in your homegrown notions of probability that you can't seem to see beyond them.
And then, from your perspective -- the only perspective you have, and the only thing you know exists -- there might as well be nothing if you didn't currently exist...
Asked and answered. In a solipsistic universe you would be the only thing that existed in it, so talking about how improbable it is that you arose in that universe hurts your argument, not helps it.
Perspective has only one effect here, and it isn't the one Toontown keeps harping on. Perspective limits your proof by essentially forcing you to commit the Texas sharpshooter fallacy in order to evaluate it. Your proof, and the model it's built upon, are then explicitly invalid. Instead, you want us to set aside the fallacy so that your model works.