Now, what would be interesting is to build a model that accounts for this "knowledge" and see if it can beat the out-of-the-box classifier :-)
I'd assume it can, and the question is: how far can a bit of manual modeling bring us?
Maybe they asked the wrong questions, but I think that's the point of the questionnaire model.
Sure, but I thought was that building an ML model that considers the questionnaire results (or existing similar findings) would be a very interesting next step.