Pretty much what you said. If "Hardcore" mode doesn't force me to rely on Survival to find food or Barter to buy it, I'm going to be disappointed. I'd actually prefer a system where most of the food items (and especially ones you find in the wild) merely delay the decrease of the food timer, not restore it. Chewing nuts and twigs in the wasteland is not a meal and shouldn't be treated as such.
The same goes for water: a handful of toilet water shouldn't quench your thirst, it should merely take the edge off and serve only to delay the inevitable.
That said, the economy is one of the most difficult things to balance in a game, much less an open world RPG. What needs to be done is to understand how players try to subvert the system to gain an advantage and try to stop them.
For example, if a player kills a ton of townspeople, grabs all of their equipment and heads to another town to cash in, the shopkeeper shouldn't say "I'll give you $50,000", they should say "Holy crap! How did you get all this stuff, you must have had to murder like 30 people! Get the hell out of here, lunatic!"
Finally, going along with the theme earlier - Todd Howard killed my dog.