I don't think this post adequately distinguishes between two concepts: how does the human utility function actually work, and how should it work.

The answer to the first question is (I thought people here agreed) that humans weren't actually utility maximizers; this makes things like your descriptive argument against perceptive determinism unnecessary and a lot of your wording misleading.

The second question is: if we're making some artificial utility function for an AI or just to prove a philosophical point, how should that work - and I think your answer is spot on. I would hope that people don't really disagree with you here and are just getting bogged down by confusion about real brains and some map-territory distinctions and importing epistemology where it's not really necessary.