One thing I really found interesting was that in Red-Listed (Season 6 Episode 4) Kirkland said that his twin brother, Michael, had serious drinking problems like his father and Red John approached him about them. Well, Visualize specializes in drinking problems so it would make sense if it was Stiles. Also, the reason Kirkland didn't see him is because I remember in the episode that introduced Visualize that a visualize member had to break off all connections with his family so he can find his true identity. Personally, I don't think it is Stiles but I wanted to make this point.