Yes. There is only one God. And He exists in three Persons. The three Persons of the triune Jehovah are each one with each other. Yes.
Yes. This is the function of the second Person of the one God, the triune Jehovah, Who, again, is one. But yes, there is one Mediator between God and man.
Ah, yes, here it comes. I will mouth the words as you say them; I know the false narrative that well… :)
…”and not an inner nature.” :)
It is what it is ~ He is who/what He is, no matter who it is denying it, Peterlag. The verbal gymnastics are… interesting, though. :)
Grace and peace to you,