... that perhaps Jordan originally planned for Demandred to be Mazrim Taim. Every single sign pointed that way, and it made perfect sense. You could say it was a red herring, but if so it's by far the biggest one he ever wrote.

It wouldn't surprise me if he planned it that way but then everyone guessed it and it was the assumed answer on forums, so he changed his mind and never came up with a better candidate. Leading, as you said, to the gun on the wall that was never used.