That's my take on Byar, yeah. Although it COULD still be Dain; both of them spent far too much time with Fain for me to ever be entirely comfortable with either, but Fain was a free agent by then so it's unlikely Graendal could use either of them much. Of course, we can always play the "we don't see the characters unless the author shows them" game and say Graendal did something to either or both of them off camera. Still seems kinda cheap, but I'm at a loss to explain how Graendal could've used any of the Whitecloacks otherwise unless she decided Galad was too pretty not to enslave (and serve him right, F--KING AVATAR111 )

The dreamspike is easier to explain: Graendal's a Forsaken, and might have thought the hostages insufficient to paralyze Perrin. After all, this is Perrin: As long as he can get Faile out all the soldiers and Aiel who followed him into battle, the people he grew up with, Rands dad etc. are very expendable. He as much as said he'd forfeit the Last Battle to save Faile, which isn't so much romantic as disturbing and ignorant (if the DO gets free there won't BE a Faile or anything else, idiot).

It COULD be a retcon, though it would be an odd one since Sanderson's following RJs notes with Harriet and Doherty looking over his shoulder. No, I think it was intentional, which makes it incredibly annoying for precisely the reason you say. I mean, really, the whole point of Compulsion is to control someone elses mind without notice: Why on Earth would you farm that out to someone else? It makes perfect narrative sense in light of what follows, but for Graendal, in the moment? We're told her supposed motive: "Graendal needed to lay him a false trail, delay him--hence her requirement that Delana create a thick Compulsion with strange provisions in it. " That's all well and good, and explains why she wanted Balthamel to supply some saidin Compulsion, but it does NOTHING to explain why she couldn't have laid down the saidar Compulsion herself sense she only realizes at the last minute what Rand intends. That's setting aside the fact that either Balthamel or Delana could Compel Ramshalan to kill her at the first opportunity.

The main thing it does is remind us all that we're reading a story, shattering verisimilitude, and that's a very bad thing.