Talking about this stuff always makes me want to go off on a diatribe about Bangs, from Sorcerer, and how fruitful they are. If I were to state it in the format of your principles, I guess it would be prepare what might happen, not what will happen. When you have a bandolier of possible conflict-rich Bangs, you can tailor the session on the fly to what your players are actually interested in, rather than plotting out what they might be interested in.