I second all that.I wrote a poem yesterday...which helped me to understand/grasp (the nature of) what I was feeling. So there.
Fi seems to work with Ni for me, making me feel very deeply, but in a non-concrete or person-oriented way. It's a flow, yeah, and you have to ride it and it's definitely introverted.
As for the judging aspect, I've noticed I can get exessively upset about injustice, unfairness, unfair representations, lies...but again, about the concept of it, the idea of it, not the result. My strongest reactions occur when I am the victim of the injustice. Otherwise I'll be empathic, but not indignant.
Speaking of empathy, an example: I will get upset when people don't make the effort to talk to a new person that's introduced into the group (a boyfriend of a girl in our group of friends, for example) and the new person is standing around in silence, but I thinks it stems from the fact that *I* wouldn't want to be in his situation, because it violates my principles, my ideas of "ideal" human interaction (and as an INTJ such situations used to be particularly difficult). I can put myself into the other person's shoes and live their pain. Now that I mention this, that's probably also what drives me to action - I go up to them and talk because I can sense their distress and it makes me uncomfortable. This process possesses an urgency that I recognise in my ESFP friend and that appears to be much less expressed in my INFJ friend. In that situation, I actually feel bad about/frustrated with the fact that the rest of my friends (except for the ESFP then) remain so apathetic, apparently they don't pick up the feeling.
I guess it's very subject-oriented despite the fact that it can come across as catering to people, which it is I suppose. This last aspect might also be the reason why I am less "dominant" in a relationship than I am in all the other parts of my life. I think that this is something that other INTJs have mentioned as well.