your beginning is some big bang from some condensed singularity[and before that?]

There is no "before that". Time started with the Big Bang. It's an integral dimension of the universe (spacetime, innit) and any "concept" of time outside that context is nonsensical.
.,,.
Yes, but this is a circular argument: it is that very 'nonsecality' that is problematical. A 'begging of the question' in the correct, or original, sense; whereby the answer to the question is taken to be subsumed in the question itself.

I refer yet again to my old thread, "What went Big Bang?", which ran for a whole year Sep09-Sep10, and to many of the posts therein.

It is not begging the question. How can it be when I make only one assertion (which, incidentally, I haven't the confidence to claim as the truth), that time started with the Big Bang and (inseparably, in my view) is an integral dimension of the universe? The rest of my remarks simply represented the egging of the pudding for pete's sake, for Pete's sake.