'God is both "Tao and the ten thousand things", but they are not different. So, if immanence means omnipresence to you, why use the word "immanence" in the first place?'

If they are not different, why does the Tao Te Ching use different words? That is why we use the term Tao (transcendence) and ten thousand things (immanence), to distinguish between different levels.

If I understand you correctly, which clearly I don't always, then we both agree that ultimately they are both the same, if by that we mean that the only 'thing' that exists is ultimately the one universal spirit.

So again we are debating the meaning of words, and how we interpret them.

I would be happy for this particular conversation to stop at this point, if that's ok with you, as it doesn't seem to be going anywhere meaningful.