Indeed you are repeating yourself, which is of no help.

Perhaps I haven't conveyed my central critique clearly enough, because you haven't made any additional progress towards answering it.

The central critique is as follows.

We both agree (because it is obvious) that people have different needs which cannot all be met by the same thing. We also agree (because it too is obvious) that in case of multiple needs, people can and do rank needs by importance, seeking some preferentially over others.

This, however, is where I no longer follow you. Why is it not the case, or why does it not matter, that this ranking can be considered as the individual converting specific utility into a generalized utility within that person: this is useful to me and it is none of your business why. If you are both thirsty and hungry, and you can either go down to the creek for a drink or forage for dates on the hillside, you are going to do one or the other (unless some even more pressing need comes up like escaping from a leopard). What is the nature of this choice, if not some sort of utility-maximization? And therefore, if we are asking about exchanges of dates, why do we insist on measuring it in units of specific utility (thereby opening up a gulf between utility and what-money-is-for) instead of this internally generalized utility-for-me? Of course the specific utility isn't actualized until the item is used to meet some specific need--but why do we care?

What extra do we learn about Alice's exchange behavior--if she buys or trades for dates--by realizing that she actually wanted dates to flavor her milk, not to eat? Or that she was going to throw them at pigeons, or stick down her doormat with them, or add to her date collection? Can't we just trust Alice that she knows what she's doing?