I wouldn't mix up "neurons do one thing" with "each thing lives only in one neuron" since he doesn't claim that.
Re the first paragraph I'm not sure what you mean by "the assumption that conflates multiple concepts that to me are substantially non-overlapping are one and the same thing"
Re the first paragraph I'm not sure what you mean by "the assumption that conflates multiple concepts that to me are substantially non-overlapping are one and the same thing"