An interesting titbit is that spells add all sorts of dialogue options for quests, even ones that you'd usually complete before you know the spells.
For example, Cali (the halfkin wolf you meet in the market) has options to dominate a Bandit to attack his friends when you reach the 'rescue tia' part of the quest. (to take one of the enemies out of the big upcoming battle before it starts)
it looks like there might be other options to whittle the number down futher, but I don't know what they are.
I think I have ALL the spells already, and I've got a stack of each type of potion. The discription is still asking me what I want to do though, even though the only option is 'attack the camp' So I assume there's the possibility of another option.
Tia herself can be entranced into joining your group as a unique slave. (though she doesn't have a portrait or anything)
I wonder whatever options there are in quests?
Spiking Emily's drink to unlock her sex-menu early is one that was easy to unlock.
The part where you have to go to the Mage Order to look for her sister has a part where you can dominate someone to get answers, or you can threaten or bribe her, or if you bring Emily herself along, she makes an impassioned plea, and you don't have to do anything.
Lots of options. I love this kinda stuff.