Many of the choices in the game do not have immediate results anyway. I know that a lot (if not most) games have it so that you make a choice, and things happen right away as a result. But in BTW, it's a build up. So there's not much of a reason for people to try to branch dialogue at all times. BTW is designed in such a way for you to pick a direction and stick with it to the end.
That being said, I would estimate that about 60% of the story content is "middle of the road". You experience it no matter what you do. The remaining 40% of story is split half on the "good" path, and half on the "evil" path.
In regards to the sex content, as of right now, you can get about 95% of the adult content on both good/evil paths. But that's not to say you get everything no matter what. I can say that all NSFW scenes get an entry in the gallery. I'm also planning to have a chapter select system at full release so that people can replay specific chapters after completing the game, and choose which variables to go with. For example, say you did the game on the good path, but want to see what might have happened in some sections on the evil path. You would be able to go back to Chapter 6, select the evil path, and jump right into it.
