Continuing:
So, what is an "Fi axiom"?
...
I was going to outline some nuances but really, your experience is your experience and I appreciate you sharing it. To me, saying I am going to dance is not an axiom. Saying I will take action even if I am afraid is sort of closer ... but it goes farther than that.
Here's an assertion I accepted for a long time: "The more you do something, the less afraid of it you will become." Just has never been proven true for me in my world. In fact, sometimes the fear just gets worse because the more expertise you gain you better understand ALL the things that
could go wrong. A better assertion for me in this situation is "Feel the fear and do it anyway." (Get on that airplane, get on that stage...) But that even defies a certain wisdom that the emotions are trying to impart. It's not listening to the core whisper ... it is missing something, something key. I need to get to the core ... to the trunk of that tree. Then that wisdom will open like a leaf, to the truth. Everything leads to a greater truth (that would be an axiom). So what is the truth about this situation for me?
Immature Fi is controlled by your emotions.
Mature Fi "controls" your emotions (through acceptance and understanding and wisdom and a bunch of things that don't quite fit into words)..
To me there's another step. Mature Fi does
not control your emotions. Heaven knows I've controlled mine plenty over the years. I used to see my massive self-control as a true aspect of maturity too. But mature Fi controls your
reactions ... it permits the emotions their right to exist. Acknowledges, accepts, whatever you want to call it. Mature Fi is like the carbon filter in a fish-tank, processing and keeping the water pure.
Perhaps I just regard what I am doing as being at a very much deeper level than what she is doing, and had we words and objective things to point at, we'd be able to show how it's different perspectives and not so much different Fi-techniques..

I know you didn't mean that badly, but it doesn't read well either.
It also might be the INTJ in me. I just swap out "rules" on the fly, all the time. It's what I do. The "rules" have no value beyond their utility. As long as the new set of rules work, and handles something new that I couldn't before, I go with the new rules..
I have to admire that in a way; my rules are not as quickly interchangeable as yours. Thus I will sometimes try longer to fit a square peg in a round hole. But my "rules" are part of who I am - they have shaped my life, I don't just swap them around ... it just sounds so easy ... so disposable. It's like your values exist outside of your core framework. Mine form parts of the key operating system.