I agree with your third point, that we need to follow the Spirit. The manuals don’t contradict the statement to teach the doctrine. The manuals are meant to be the foundational material. What comes out in the course of the lesson should depend on the spiritual maturity of the class. I have been in classes where the Spirit brought out surprisingly deep points of doctrine, but those points are learned individually, and not by the class as a whole. The gospel cannot be taught to a whole class on the same level. Each person will receive what they are prepared to receive. We give the material as we understand it, praying for the Spirit’s inspiration to enlighten their minds with the truths each person needs to learn. What they learn may have nothing to do with what you just taught, but everything with the Spirit you just brought into the lesson with your preparation. That emphasizes the point that we do not do the converting, the Spirit does that. Our job as teachers is the come prepared with material and the Spirit then the Spirit does the rest.