Uh the title literally says, a "story of corruption" and your surprised when it has less material on the straght and narrow path? The story by design is made to play the corruption route. Most others I have played in the past, if you choose the more straight path, that's exactly what you get, less content. More reliable, rightous people don't do lewd things, lol. I am not trying to be a smart alleck here, but common sense says the more corrupted you are, the more you'll do. Thus, more content.
I get the part of it being tied together. But again, all the "corrupt" type games I played, you have to gain corruption points to get certain material and unlock certain parts. That may mean you have to play it through a couple of times to see everything. It's pretty common with this type of game. Like the del.mar said, create a separate save near the part you need to unlock, use the editor to up your corruption, then load it to continue playing.