Oh I absolutely agree, because most small scale growers would have a kitchen system, meat would be ill advised because of the duration of decomp, smell etc. But you are right you can add that in moderation.
Eggshells can be good when ground fine, but they can also cut the worms so I am personally careful of that - plus personally I would rather just feed that to the BSF which are much more ferocious in their consumption :D
at this stage I am still busy trying to get the populous up, as the drought really cleaned house so to say, I have lost a great deal of live stock as well as crops and orchards, and the worm bin suffered a bit under that as well - but I will get back on that horse :D