Niara, apologies for responding an internet year later. I don't have a good excuse, I just wasn't in the mood to discuss video game matters.
Wren, my poor little halfing bard with her negative constitution modifier and hoplessly idealistic, many-chance-giving heart can't even carry one - she'd be driven to the ground in a weeping, distressed mess, unable to move, just trying to hold onto a single coin, I think... she would never dream of taking its energy by force; the concept would horrify her... but she might ask it to help her, and and she'd defintely want to know who they were, and if there was anything she could do to help them...
Sure and any DM would call that good role playing. The concept of that module seems to rely on creating such tension -- "you won't get out of hell with your soul intact". It's an interesting variant on the genie in the bottle problem. Even the people who wished the genie free on the third wish benefited from the enslavement of the genie.
On a straightforward reading of the text, you are correct, well argued. But I think this needs to be revised. If the text states that using all three charges and declining any benefit at all are equally good acts that a problem with the text.