Okay. Here is my two cents on Talm:
1) I believe the reason he at least appears to be less broken than the others is simply because he was the only one who actually followed the rules of the Oathpact.
2) The fact that Jezrien said the Oathpact was dissolved doesn't actually mean that was true. Since Talm was forced to return, he followed the rules of the Oathpact, and since at least one of them did so, the Oathpact was still in force.
3) By this logic, I think the reason the other Heralds are all insane to various degrees is (a partially due to their lengthy lifespans, but more importantly (b a direct result of ignoring the Oathpact.
4) I agree that the perception of others gave Talm a leg up in terms of survival since he was seen as unbreakable by so many. That tracks with established Cosmere logic.
5) None of the other main flashback characters are anywhere near perfect, and I think Brandon wants to keep as little known for certain about the Heralds themselves as possible for now since they will play a larger role in the back half.
6) Therefore, I think readers will largely continue to see Talm as perfect either until Talm's own book, or that of Shalash depending on which Brandon writes first.
7) Essentially, Talm may appear perfect now because he followed the Oathpact, but that doesn't mean readers will maintain that view once we actually learn more about him from those who know him well.
8) If this logic holds, I have no problem with Talm's current characterization since I believe the events of the back half are bound to (a give readers more information, and (b Set Talm off on his own evolving character arc. Sanderson has earned my trust more than any other author, so I have confidence that I'll enjoy the end result, even if it doesn't follow this train of thought
Apologies if none of these thoughts are original. I didn't look at the full thread prior to responding, just the initial post.