What are the consequences for giving all of the deceased personal things to charity?

We can't answer your question because we don't know what the will actually said. If it allowed the executor to dispose of the personal effects however they saw fit, then the successor executor (who I assume is person C) would be within his or her legal rights to give them away to charity. But if the will provided that all the personal effects were to go to B, even if she or he resigned as executor, then the successor executor did the wrong thing. You should go back and look at the will to figure out what was required. And, if it the executor did the wrong thing, then she or he should make a claim against Person C.