Yes, I agree that the states were not delegated all powers not expressly delegated by the constitution, but "the people and the states" were. I have never heard a better explanation for the 10th amendment than to say that it was restating the enumerated powers doctrine (though I cannot recall where I first heard that explanation). If you have a better explanation of the 10th amendment, I am very interested to learn what it is.
Regarding your second point: the change was not "states" vs. "people and the states". The change was whether the rights referred to were solely those expressed in the Constitution, or something broader. Broader won. This is an argument you are going to need to take up with the authors of the Constitution, because they do not agree with you.
Regarding (5): The framers in fact rejected a previous iteration of the language of the 10th Amendment that would have reserved to the states any powers not expressly delegated in the Constitution. So we know that's not what they meant.