Rabbi’s lesson

You teach Gemara, Gemara is a book. It's just that you deal with what you have to say about it.
They are interested in hearing what the rabbi has to say about the above books.

Indeed so..

That's exactly the difference. A Gemara is not a book in any essential sense. Except that it is bound and made of paper.

Surely you have read many basic books, whether in Jewish philosophy or in general philosophy, and so what is the problem with a rabbi studying a book and saying what he agrees with and what he disagrees with, what makes sense and what doesn't?

And regardless, I don't know exactly what the rabbi thinks his goal in life is, is it to study Torah for himself? I don't think so, I think the rabbi's goal is to lead Judaism/religious people to another level, and therefore the rabbi should do things that will bring in and help a greater number of people even if the rabbi thinks it's not ‘ideal’, and I don't mean that the rabbi should say things that he thinks are wrong or that the rabbi should not say things that he thinks are right. But just as, for example, if the rabbi changes his style of formulation a little in relation to the Rishonim (and as explained in “On Style and Essence – Clarifications and Basic Assumptions for Readers of the Site (column 63)”), then a much larger target audience will be exposed to and accept the rabbi, and it seems to me that even if the rabbi studies a book like Derech Ha’aretz/Da’at Tiv’onut or even Moreh Bemuchim (which is less critical because many academics are already engaged in this…) and then says about it, “It will be very helpful.”

I understood that this was your opinion, and I replied that it was not my opinion.
Maybe you didn't notice, but I teach a lot of classes and also write a lot, and anyone can read and learn my thoughts and opinions from them. You suggest that I also study such and such books, and I replied that I don't see any value in that. Whoever wants to learn from me should study what I teach and how I teach. What you think is important - you study it.
My opinion on these books and the like appears in several places, and if you've read them, you can understand for yourself why I don't see much value in them and in studying them.
Of course, I have no problem hearing suggestions for improvement, but in the end, I'm the one who decides what I think is right for me and what isn't.