Joy, the one thing I do find interesting in your analysis though is that you're willing to go beyond the realm of psychology here. I think that essentially, the nature of the types is about phenomena...that is, the types transcend psychology. Nevertheless, it's also helpful to remember that typically, Socionics is talking about how people perceive and process things.

Therefore, the fact that everything you do is both internal and external doesn't mean that everyone is equally introvert and extravert at the same time. The issue is that people's awareness is directed more in one way or the other, and that it's hard to see equally both ways...

Kind of like those pictures that look different depending on how you look at them....or like the pictures of cubes that go in and out...and it's hard to see them both ways at once.