I think the quote you have given above was discussing the potential value of mealworms for human food, not hedgehogs. However, I think in any event, you are missing the point regarding the research mentioned above. It was not discussing how much protein there is in mealworms, but that the Calcium Phosphorous ratio is not appropriate for hedgehogs (and other species) to be fed dried mealworms exclusively or in large numbers. They can lead to the deformities and pathological fractures mentioned above. Some hedgehogs, especially hoglets apparently become addicted to meal worms – hence the deformities. I have heard that some people who look after sick or injured hedgehogs sometimes have to wean them off mealworms, because they refuse to eat anything else. I am pleased to hear that you do not feed mealworms exclusively.
I find that the hedgehogs here also tend to prefer drinking out of a mini pond in a large saucer which is refilled with rain water. Sounds similar to the ones there.