To maintain our prior context, kindly cite any supposed sources where the mages of the Circle advocate rounding up apostates.
Um, Keran saying "[the mages] want the Circle to work the way it's supposed to."
Registering all mages within the Circle is how it's supposed to work.
Pending the dialogue options chosen, when you encounter Wynne in the Broken Circle quest with Morrigan in the party, Wynne will attack your party simply for harboring an apostate. So there's another one who does not advocate letting apostates run loose.
I would also argue that your assertion doesn't quite work, because plenty of commoners in our own history supported oligarchies and monarchies that could inflict terrible injustices. Most people will do whatever happens to be easiest, regardless of how right it is.
We're talking about the very group of people you believe is the subject of injustice, not just some commoners who are not involved in the matters directly. They were kicking back against the Templars' management of the Circle, so it's not like they are oblivious or apathetic to mistreatment. They were not kicking back against being housed within it. There's an entire fraternity of mages that do not subscribe to the idea of freeing all mages.
And, criminy cripes, if they are Andrastrians then it's basically their religious belief.
I think part of the reason I disdain this whole libertarian nonsense is because it reminds me of ignorant people IRL that trample over people's religious beliefs and religious freedoms because they believe the religion is oppressing them and that they must be freed -- it's not your place (universal "you") to fight for others' freedom if they haven't asked you to. In "freeing" them they have committed oppression themselves.
Meredith had been aiming for Annulment anyway.
So, like I said, the Circle by itself would not have hurt nearly as many people.
Meredith's red lyrium idol was what was pushing her to that end goal.
Well, she could do what she wanted to do with Kelder. But in this case, it really wasn't necessary to do anything, because other elves took care of it, so she could have just laid off the Arishok and not started a war.
I'd say the news of Isabela's escape with the tome is when the Arishok decided to do what he did. It just wasn't made official until Aveline confronted him.
I mean, he and his men were armed and ready when she and Hawke walked in.