Hunter, thank you for wording it so succinctly!
Are you saying that Lysaer would behave similarly even if he weren't cursed? He definitely had doubts about the clans and F7 in the beginning of CoTM, but usually doubts end up strengthening our original principles, not becoming alternate values. That part was Desh-thiere, not Lysaer.
And I don't think Morriel is worrying about right or wrong at this point. She's too wrapped up in her bid for power.
Your thoughts are VERY clear and insightful
Hunter, I see what you're saying about the Koriani taking free will and 'amplifying' it. But at that point it no longer is free will and changes into something else; perhaps enslavement is the word? At one point in the saga I remember Koriani discussing who to peg for some task or other and not being able to find anyone with a flaw they could exploit. This clearly indicates that there needs to be ground for the enslavement of will to take root -- and you're right about the s'Brydion not taking much for them to twist.
I think the curse took Lysaer's nature and made it one-sided - successfully wiping out all the parts of him that tempered justice with the other quality he had (what it was escapes me at the moment). The curse in effect wiped out Lysaer's ability to see the other side of things as he is very well able to do in The Curse of the Mistwraith.
As to who is right, it must be the one who is not willing to sacrifice the lives of others to get what he needs, and that is hands down, Arithon. What he discovers about Alithiel in Davien's maze is that it is never to be used for killing and what it does in Stormed Fortress is take the will to fight out of everyone who can 'hear' its truth. Asandir does the same thing with the forest when Lysaer would have burned it down. The men went into a suspended animation and when they awoke were totally unwilling to fight.
Chana, I'm not sure if there's a difference between the necromancers and what Morriel did. I'll have to think about that a while.
Hunter - I'm still not sure I agree with you about 'amplifying/inflaming free will'. If someone is actively controlling the actions of another person, even if they use what is already a part of that person, I don't think it can be considered 'free will'. When the Koriani provoked Arithon with the fetch at Riverton he did not have the option to control the curse because it wasn't within his ability to do so. They basically forced his reaction.
Sandra - When Morriel possessed Selidie the Fellowship could not take action, but when Lysaer was possessed they were able to help Sulfin Evend save Lysaer. This implies a difference, I just don't know what it could be.
I believe the difference is that Selidie gave permission for Morriel to do this. All initiates give over their hands, mind and body to the will of the Matriarch. Though i'm sure she never imagined the extent to which that would happen, it was part of her oath.