First of all, you know that an auteur is a filmmaker and not a writer, right? Just checking, Ohio.
And you’re right, “The money’s in quick, light books that use small words and translate well to the screen, preferably featuring a gifted pre-pubescent with supernatural powers and/or a thirst for revenge.” But even if you manage to pull that off, you still have to go through the BS of finding an agent who will read it. Then, if you can sell an agent on it, that agent will tell you you have to market the book yourself (uh-huh) even if some publisher is willing to publish it. Until and unless it becomes a best-seller. No one is willing to put money into an unknown. Period.
So. Then you ask the big question, "SHOULD I..." to which I claim to know the answer (I do). It’s the middle road. It’s always the middle road. You learned THAT when you went through your hippie phase, didn’t you? You do neither. You learn to write something readers will actually enjoy (assuming you can get them to read it) but that rises above the level of common trash.
I’ve been doing it for years. When I can get people to read my crap, they actually enjoy it. Getting them to read it is the difficult part. Refer back to that business the agent tells you to do and now you understand why they tell YOU to do it.
Want to give me your coffee money back? You know I'm sitting here staring at you the way you're staring at me right now... It's very uncomfortable.