I don't think that the translation of the Creed is incorrect.I am using the translation of the Creed that you copied out in the O.P. If you believe that it is incorrect, why did you use it? Just read it again; it is perfectly clear. One Person in two natures.
Now where have I ever removed 'inseparable'? If I had, it would indeed have been a form of Nestorianism, but of course I never have and so your allegation is false. What I do say is that you cannot take the word 'inseparable' and bounce up and down on it like a trampoline without taking into account the other words in the Creed. The Person of Christ cannot be separated into two as Nestorius sought to do, but He has a human and a divine nature. As man, He could be in only one place at a time (John 11:6, 15) but as God He was in heaven at the same time He was on earth (John 3:13), but it is the same Son of Man. If you say that as God He could only be in one place at a time, you have made Christ less God than God.
Not my use, but the usage of Chalcedon and all the Protestant confessions that I am aware of. Are you possibly confusing the ousia of Nicea with the physeis of Chalcedon?
You removed "inseparable" in your explanation (Jesus did something in one nature separated from the other). We have to treat all of the descriptive words of the two natures as a whole (as the Creed itself shows). The Creed was formed to combat heresies - we can't look at the natures at one time as being distinct (without "inseparable") and at another time as inseparable without being "distinct".
The descriptions the Creed offers were not meant as choices we can use to fit into our theories but rather how the authors of the Creed believed Christ's nature to be. Your view is, I believe, reflective of postmodernism because you want to adhere to the older things of our faith but only on your own terms. So you redefine "nature" to mean "person".
My only point is that when Jesus suffered this demonstrated His humanity. But Jesus did not suffer apart from it being in both natures.
The confusion you have now is what caused division shortly after the Creed. You are using "nature" as if it were "person". Jesus did not suffer in any nature. He did not calm the sea in any nature. Our nature is demonstrated by our actions and what we can experience. But we experience things and do things in our person.
This is a form of Nestorianism because while you affirm two "natures" you change the actual meaning to "person" in practice (i.e., Jesus suffered in his human nature because God cannot suffer). It is the same as saying God did not become flesh because God is not man and God is spirit.
That is why I asked if you really believed that the Word became flesh. It isn't because I doubt you do but rather than your theory dictates you don't. You are inconsistent. But given your intelligence I believe it is something you simply have not thought through.