But don't feel bad. I was corrected for 'extravert' by an English professor once, and felt the need to politely explain my usage. But I think the distinction's lost. Most psychologists probably wouldn't use "intro/extra" because "intro/extro" is easier.
Not really, no. At least not here. Just to say that Jung, when using these terms, had something particular in mind.
The above way in which you suggest "most people use the term" is so far from the original meaning that I think it renders this common usage rather needless and confusing -- why not just say outgoing? This is just my view as both a very keen reader of Jungian psychology and an outgoing introvert -- I felt compelled to comment!
If you are going to use a minority definition, however correct, it might help people if you said that you were using the word as Jung did rather than the common meaning. When a definition strays a long way from its original meaning, it helps if you indicate that you are going back to the term's roots.