I still do not understand why this is atheism. Why is a pantheist basically an atheist?
What is the difference between what he says and panentheism? Why do you think there is really nothing behind these words, and that they are just empty words?
I understand that calling things by a name says nothing when there is nothing behind it, but why is there nothing standing behind the words here?
Maybe in other words, I do not really understand what it means to say “God is nature,” and what Spinoza’s general view and that of people like him actually is—and in general, why it contradicts the approach of Judaism and theism in general. (And of course I would be happy to hear an explanation…)
Thank you very much!!

You wrote, “When one calls the totality of reality God, that is merely giving it another name.” What is non-believing about that? What is atheistic in that sentence?

I answered and exhausted the point. I do not see any point in repeating the same explanation for the third time. All the best.

If I may, look at the second booklet on the cosmological proof and the third booklet on the physico-theological proof (if I wrote that correctly). From there it becomes clear why this bothers Rabbi Michi so much.
Personally, I am not so sure there is no value in Spinoza, but it seems to me that Spinoza himself would not have minded being an atheist, so there is no reason it should bother the questioner on his behalf.

And with the Rabbi’s permission, I will expand.
You could say that Spinoza has what nowadays is called a religious experience of the universe. In practice he is an atheist, but he has a religious experience of the universe. But as Allan Bloom wrote in the book “The Closing of the American Mind,” a “religious experience” is like an old toothless lion that sociologists and anthropologists tie near the house in order to experience the thrills of the jungle. From Rabbi Michi’s perspective, this is not serious. In fact, this is exactly the thing Rabbi Michi has been fighting against for twenty years. From his point of view, the religious experience changes nothing either way. Either there is a God and His command is absolute, or there is not, and then leave me alone.
There is a bit of fear in this approach. What happens if Rabbi Michi suddenly decides that the proofs he writes do not hold up, and he and all his crowd of followers decide that that is it, there is no service of God? And nevertheless, “For no hypocrite may come before Him.” You cannot flatter Heaven. Things have to be true, and true all the way through.
And therefore Spinoza is not interesting to Rabbi Michi. As a philosopher, he is interested in seeing whether anything can be learned from him. But Spinoza’s religious experiences interest Rabbi Michi about as much as the peel of a garlic clove. Hence his sharp response.

I do not know about the fear of the worthlessness of worship based on experience without belief. It is utterly without value. Is there nothing to fear from that?

But in your view, is there room for belief without proofs, just on the basis of the tradition I received from my ancestors?
In other words, what is the role of proofs in your approach—to clarify traditional belief, or to replace it?

Definitely yes. If the tradition seems sufficiently reliable to you, that too is a completely valid proof. A proof is always based on assumptions, and therefore it cannot replace them. The role of a proof is to clarify to myself that I do indeed believe, and if such clarification is not needed, then not.
See a bit about the role of proofs here:
https://mikyab.net/%D7%9B%D7%AA%D7%91%D7%99%D7%9D/%D7%9E%D7%90%D7%9E%D7%A8%D7%99%D7%9D/%D7%90%D7%91%D7%A8%D7%94%D7%9D-%D7%90%D7%91%D7%99%D7%A0%D7%95-%D7%95%D7%9B%D7%95%D7%91%D7%A2%D7%95-%D7%91%D7%A9%D7%91%D7%97-%D7%94%D7%A0%D7%97%D7%AA-%D7%94%D7%9E%D7%91%D7%95%D7%A7%D7%A9/
and also in Two Carts (and Truth and Not Stable), of course.