In terms of the Fe, I'm interested in diplomacy and in keeping things smooth in terms of everyone feeling comfortable and having their feelings accommodated. I am generally very tactful and have been told I come across that way. I feel that smoothing things out in that area allows place for all the other good stuff like progress, personal development, etc. I am quite a big fan of social conventions if they make everyone feel comfortable. I (almost) always take others' feelings under consideration, apologize excessively if I feel I'm possibly being rude...etc.
And personally, I am ruled far more by my heart than my brain, though INFJs often have a split where they can be very logical about something but still overwhelmed emotionally - that's very much me.
My brother is an ISTJ and I am less and less like him as I get older, I'd say. I genuinely think I have very little Si. I have a lousy recall for details and that sort of thing. He has ice hockey statistics memorized and at his fingertips going back decades. He is also very unwilling to talk about his feelings and doesn't seem much in touch with them - or he is immensely private about them.
You've really found that from reading a few lines by someone you don't know either IRL or online, you can type them accurately?? I'd really question if anyone can do that.