Finally, in the last few months, I've begun to understand MBTI. There are no logical inconsistencies in my understanding, and I can break down any behavior into functions. The problem is, there is always more than one way to describe a behavior from a functional standpoint. Ne, Fi, Te, Si can solve the same problem that Se, Ti, Fe, Ni can solve. They can explain their thought processes in the same way.
I've mistyped a few of my friends -- for example, I thought one of my friends was ENFP since I met her, and I recently realized she was ENTP. But during our entire friendship, I felt like I completely understood her and her thought processes. I could predict her reactions to other people, to ideas...I "got" her as well as I got anyone (and I pride myself on ability to deeply connect with/understand people). And I thought she was ENFP at the time. The thing is, once I realized she was ENTP, absolutely nothing about my understanding of her changed. The same is true of my INFP friend that I thought was ENFP. Same with my ENTP friend I thought was ESTP.
I can completely connect with people (almost on par with therapists), and I essentially don't use the MBTI framework at all in doing so. If anything, it's hindered my ability since I'm losing information trying to shove an irregular shape into a regular-shaped-hole.
MBTI has practically no application in my life. The only thing I can think of is that it may be helpful for me to explain one person's behavior to another person. Even then, it's a gross oversimplification of total behavior. It says nothing about specific motivation. And honestly, even in using the framework to explain people to each other, I feel that I'm leading them down the wrong path. It certainly isn't enough...