I am always amused at how confident Lae'zel is in her superiority. Like she is literally caught in a cage about to get killed off by two tiefling commoners and yet she still acts like she is irreplacable. But I also have to hand it to her, that she backs that up. The standard solution to every challenging encounter is to simply apply Lae'zel.
When you play as Astarion, right after she tells you that controlling the tadpole isn't an option, you get dialogue options telling you how tasty she smells - and that was the end of Lae'zel in my first Astarion run. ^^
I do like adversity best, when it is used to learn more about the involved characters and helps to bring them closer together because their relationship gets stronger through the conflict. Gale has a great example of this: When he first asks you for magical items, you can push twice into his mind to find out why he is so cagey about the reason. If you succeed, you can simply go on without saying anything but you also are given the options to be terrified or to feel bad about your transgression and confess. Gale understandably gets angry and you have to persuade (or intimidate I think) him into seeing your side of the situation, if successful he relents and is happy about your support, if you botch too many of these rolls he might leave because they cause pretty strong disapprovals. It's such a good scene because I can understand both sides of the conflict, but I especially love it because it allows for more complex player emotions, you can be scared of the orb and you can feel bad for exploiting the tadpole and try to fix it.