Part of how I reached that conclusion was the J vs P difference, actually- or what Jung terms rational vs irrational. Introverted intuition is an irrational (or perceiving) function. His explanation of the introverted irrational types fit me far more than the introverted rational types, which is what Fi is.
Basically this is a theoretical disagreement. MBTI categorizes INFJs by their auxiliary function vs their dominant function. That strikes me as a really dumb way to do things. It's like saying an INFJ is more Fe than Ni. For this reason, honestly, I think many INFJs are probably actually ENFJs. I think Vicky Jo is quite likely one of them.
I find it interesting that you mention behaviors and then list behaviors Vicky Jo states are the difference between the two types. The behavioral focus of MBTI and cognitive functions is what turned me away from it in the first place and on to enneagram. I am far more interested in my motivations, which is more of the enneagram emphasis. MBTI always struck me as a little shallow and trivial. But then I read Psychological Types and I realized it's just that MBTI is stupid, not the original text of Jung's.
I admit that I'm not completely sold on Fe being my auxiliary function. I think it's entirely possible that I use Ni-Fi, or that my auxiliary shifts between Fi and Fe depending on the circumstance. More than anything I'm an introverted intuitive feeler. But I do suspect that I am a Fe auxiliary, and I think it explains something quite well about myself that I haven't been able to put a finger on with my former typing of fi-ne.
To answer your question- I do both directing and informing. It depends on the situation and the context. I find Vicky Jo's way of determining type to be extremely flawed because it is a laundry list of behaviors and that means nothing to me. I'm looking for the gestalt. Laundry lists strikes me as arbitrary. My favorite sources as far as all of this goes have been Jung Psychological Types, Lenore Thomson Personality Type, and Naomi Quenk Was That Really Me?