Now here's my question, is Tavarangian allied with the ghostbloods? Or a separate organization all on his own?
I was under the impression that Tavarangian was the leader of the Ghostbloods, but I may have misunderstood the section.
If he is part of the ghostbloods, then him and Kabsal would have to be from different factions with different goals. There wouldn't be any reason for an assassin with poisoned bread when your cooking staff makes all of Jasnah's meals. Kabsal hides himself when he and Shallan are in the garden and they see Taravangian and Brother Ixil. The question is, did Kabsal fear being recognized, or just the questions that would come from him not being recognized?
If there's one thing we know about Taravangian is that he is sly, and trying very hard to hide who he really is. We have already established the fact that Taravangian didn't need a soulcaster, and he most likely brought Jasnah there to see if she could soulcast without a soulcaster. Establishing that she can, he wanted to get rid of her, so he sent Kabsal, someone who seemed completely untied to him in any way, to kill her. Even doing it in his own home will divert suspicion from him because no one would believe him to be that arrogant to think he could kill someone in his own home and get away with it. Who else is better. I think Kasbal hid from Taravangian and Brother Ixil, one to seem unrelated to Taravangian and two because he is not a true brother of the order Brother Ixil might wonder who he was.
When Gavilar died:
The king coughed. “You can tell…Thaidakar…that he’s too late….”
“I don’t know who that is,” Szeth said, standing, his words slurring from his broken jaw. He held his hand to the side, resummoning his Shardblade.
The king frowned. “Then who…? Restares? Sadeas? I never thought…”
Amaram after Kaladin kills the shardbearer:
“…why Thaidakar would risk this?” Amaram was saying, speaking in a soft voice. “But who else would it be? The Ghostbloods grow more bold. We’ll need to find out who he was. Do we know anything about him?”
“He was Veden, Brightlord,” the stormwarden said. “Nobody I recognize. But I will investigate.”
...skipping stuff...
Amaram shook his head. “You’d have changed your mind. In a day or two, you’d have wanted the wealth and prestige—others would convince you of it. You’d have demanded that I return them to you. It took hours to decide, but Restares is right—this is what must be done. For the good of Alethkar.”
On the other hand, how many organizations have access to Soulcasters?
Btw who is Thaidakar? At first I thought he was some random name who would become apparent in a latter book, but it seems I have missed his name a couple of times (i'm not very good with names and i haven't got around to my second reading yet). Do we know who he is, or are we only making wild guesses?