My number one point of distrust lies in the Diagram. They make a big point at the way his intelligence at that point is such an outlier that they are never likely to see anywhere near its level again. Or just as likely, such an outlier that it has never happened at all.
I'm thinking that his condition has somehow left him vulnerable to outside influence, in the same manner as a stormform listener. The every other letter bits even remind me of her "screaming" while in that form.
The big question is whether the influence is Odium or Cultivation. But since it instructs them to kill Dalinar only if he turns away from the path of a bloodthirsty warlord, and calls for him to sow destruction far and wide in the name of the greater good, I'm betting that the influence isn't benign.