Unless you actually have quotes and selections from the series where a character clearly identifies Alviarin's mark, the Shadowspawns special abilities and the Dark One's reality bending powers, you're operating entirely on theoretics.

You won't find those quotes and selections...because they are not there. I'm primarily interested in channelers and as a result of this, I've read the BWB and most of the Power/Forsaken/Channeling related sections of the books multiple times.

I think you are so quick to name the True Power as a source for anything Dark-related that you forget that the taint of Shadar Logoth, Dreamwalking, Wolfbrother/Wolfsister abilities, Sniffing, and indeed parallel dimensions and other lifetimes have nothing to do with the Power.

You also forget a key factor: The One Power is not the Creator's essence; from all we have been told, it is the force the Creator put in place to drive the Wheel of Time. The Creator may have originated it, but we don't know if it is Her essence or not. The True Power, conversely, must operate on a parallel path - it is not the Dark One's essence, per se, but an additional force that the Dark One can control. The Dark One is a sentient intelligence from beyond space/time - it's not limited to using one force to accomplish it's goals. In fact, we've seen no evidence that transmigration has anything to do with the TP, either. Once again, if you are going to be so insistent about this, provide a quote or section that says so. I suspect all you will find is the same thing the rest of us found - a bunch of uncertain statements that don't suffice to substantively answer or refute most people's questions.