I'm sure that worms will eat honey. They will eat candy. Try a small amount, and see how it goes. I would be careful about feeding too much. Sticky bedding is a bit messy to work with. Also keep in mind that honey is a preservative, so it will resist breaking down.

I think you would have to put in a LOT of egg shells before the pH of the bin is skewed. Remember that egg shells are mineral, so they are not food for the worms, though the attached membranes are.