Im at the point where I have to craft an antidote for her. Ive been given 3 choices and explored them all, what I'd like to know is if she has more quests afterwards (is it possible to get her as a slave/servant AND learn the Dominate spell).

Wiki has many answers :)

http://strive4power.wikia.com/wiki/Chloe

But yes, it's possible. Give her the normal one and learn Domination.

Then keep going back - at some point she'll ask to join you - not sure what the requirements are, but it's a random event.