Teriana does not receive the protection from torture the other Maarin received from Madoria but the goddess protects the fleets from Gespurn. Teriana never earned the goddess' disapproval in the first place. After all, Lydia never talked, the book was the damning evidence which given to Lydia was at Magnius' suggestion. Not only that the goddess likely approved of Teriana's decision. What would have happened if the Quinsence had taken Lydia West? Most likely - Hegeria marking her long lost chosen and owing Madoria a favor. Madoria is heavily implied to have saved/pulled Lydia to the West herself. Teriana just selected herself as being able to see past old structures and react to the present so Madoria wanted her to stay on the board for the upcoming war.
Why does Madoria have a presence in the East? Because the Maarin sail in the East and they worship her.
Similarly Magnius reports Madoria as believing that the Celandor Empire would find xenthier crystals to the West - even if other gods disagree. Madoria is the only one of the Six with eyes on the East.
Furthermore - Dark Shores events are somewhat behind Dark Skies. By the time Teriana and Magnius speak enroute for the doldrums, Lydia has been in Mudamora for days or more. Via a xenthier crystal, with the implication from Hegeria that Madoria was directly involved. Add in the description of "liquid hands" when Lydia was pulled by the current down the bath house drain - Madoria knew of a xenthier crystal in the heart of the Celendor Empire. The Goddess of the Sea knows that it's only luck that the Celendor Empire hasn't already found out about the passage.
Why is Gespurn present in the Doldrums? The Doldrums are powered by his marked - in essence it is a zone created by those who are his hands in the world. Why wouldn't he be present?
Moreover - even in the event that Gespurn wouldn't have noticed the campaign sailing through the dead zone he maintains - Lydia and Killian already discussed the events occuring in the East. Direct eyes in the East the gods besides Madoria don't have. But Mudamora is fair game.
And why does Gespurn become directly involved - he's the one who created the Doldrums. Of course he's not going to let the Celendor legions sail through without attempting to stop them.
Killian unknowing spells out with Lydia one of the reasons it's so hard to notice a Corrupted in time. They don't look like fighters. Killian is right when he says Lydia is a brawler, she's not skilled nor accurate with weapons but is durable, strong, fast and is capable of draining at a touch. And Lydia certainly does not look like a fighter with her lack of scars, calluses and unbroken nose. Her healing rate however guarantees that she won't scar except in cases of her out right losing body parts with even broken joints healing straight without intervention. The Corrupted are the same - faster and stronger than they look, and simply do not scar and can possibly even regrow teeth.
Dareena when she reinforces Killian's force states that Malahi excluded her from her plans. Malahi does not protest. Earlier however Killian narrates that Dareena did not agree to come. The reason for the discrepancy? Malahi lied.
Hegeria's mark is intended for healing - so why the general physical strength increase? Part of it is just the methodogy of how Healers heal - drawing in health for their own recovery so that the Mark isn't an instant death sentence. But part of it? The Healers are aging while also actively helping individuals. The extra strength is both side effect and helpful required secondary powers for moving patients and to help get to patients.
