This really turned into an interesting thread, lots of opinions, all viable. I think it is good we share our thoughts, good or bad, makes one stop and think.
As for eating egg shells, yeah you can, just be aware if they go in, they must come out and that can get pretty painful with all the little jagged edges. Trust me, I have eated pinion pine nut shells, good thing I was very young and healed quickly. I learned how to crack them open after that Boy Scout outing in NM!
Have a good weekend, all.