By berelinde

I have a complex relationship with Vivienne. On the one hand, I respect and admire her determination and her resourcefulness. On the other, she never introduces me to her seamstress! That is unacceptable!

By DreamSever

I hated the fact that just to get her approval and side quests I had to lie about the circles being good, I didn't want to do that but she greatly disapproves if I don't

By berelinde

^^ You don't have to support the Circle system, you just have to be evasive. She approves of the choices that say that you want to restore order, too. I've managed to get her up to max on 4 separate playthroughs without ever once telling her that I support the Circles.

- During the first conversation, tell her "This chaos hurts everybody." That nets a Greatly Approves, and it isn't pro-Circle.

- After making the mages full allies, you can win back twice the approval you lost by telling her that the you support mages as chantry clerics and by saying that you want the mages watched.

- Vivienne respects power and appearances, too, so it's possible to gain a great deal of approval by telling her that you'll heed her advice about keeping up appearances. 

By Anonymous
I just take her to the Deep Roads with no armor, weapons or accessories and let the ogre beat the crap out of her.
By Guest
You don't need her for the recruit in the Hinterlands. Just get the Arcane knowledge. In fact, you don't even need that if you are a mage.