At this point, the killjoy jumps in and says...
the Myers-Briggs, despite being wildly popular for reasons that personality psychologists cannot fathom, is neither a valid nor a reliable (your scores will change depending on when you take it) predictor of anything. It was created by a bored housewife based on a now largely discredited field of psychology (Jungian). The publishers of the Myers-Briggs are laughing all the way to the bank, which is possibly why they've never made the time to publish any validity studies in respectable peer reviewed journals. Although, the descriptors are vague enough to roughly fit about anyone's personality, making it appear valid to people on the face of it. So, if it's fun to chat about, then enjoy. But, don't take it seriously.
Now back to your regularly scheduled programming.
I hate to say it since I used to love taking the Myers-Briggs tests, but I agree with this analysis. I also think that some of the axes might be more valid than others. I've found the I-E axis really useful and I think it does correspond to something real in many people's personalities, but P-J and T-F? Maybe it's just me because I seem to always fall right smack in the middle of these axes, so I usually come up with something like INXX as a type (which really isn't that helpful).
But then one day, I realized that I'm not really middle of the road when it comes to (T)hinking and (F)eeling, I am both a strong thinker and a strong feeler. I feel very comfortable thinking and feeling and this shows up in my life. For my undergraduate I was in a double degree program in Computer Science and Vocal Performance (think opera singing) and was very good at each. I really enjoy analyzing things and making these works and yet I also understand both my emotional life and the lives of others.
Moreover, philosophical neurologists (like Antonio Damasio) have theorized that emotion is not the opposite of reason (in spite of centuries of philosophy that has organized itself in part around this opposition) but instead that our reasoning abilities depend on our emotional lives.
I also think there might be something wrong with the P-J axis. A couple of signs of being a J are being organized and good with deadlines -- being a finisher, vs. preferring things to be more open-ended. What can I say? I think I (and many other people) are very much both depending on the situation. For certain things I really like being orderly and getting things done on time or even early (like when I do my taxes). When I am writing a long, complex, emotionally-charged letter (email) to a friend, however, I prefer to take my time, put the letter aside, rework it, put it aside again, and then finally send it (or not) as I see fit.
I have mentioned these problems to people and have heard that I really need to have the test administered by a professional. Then, I think: "Ah, yes, I might have believed that in my 20s, but I have been around the block of few times ..."