well, i know people are divided, but my personal opinion is we can use both the introverted and extraverted attitudes of each of the processes.
i am a Fi aux who tends to surround herself with Fe doms so maybe i can offer some thoughts on our differences that i've observed? i don't know if we can ever totally change our personal style, but i think we can definitely learn some behaviors from the other side of the fence.
Would Fe come from just thinking about how my actions affect those around me, and putting them first, or is there something more to it?
the thing that i think differs Fe from my Ne-lead Fi (which apparently frequently looks like Fe to others) is that Fe users seem to prioritize interpersonal dynamics over intrapersonal dynamics. Fe users look at relations
between people. whereas i think of Fi+Ne as "pinging" between two people - check one person's mood/affect/values/etc and then check the others', then see how they match, and analyze the situation based off that. but Fe users don't seem to work that way... they check action-consequences, like you said, and impact. they seem to look at the lines between people, instead of pinging back and forth between people. and so that's how they see what i miss. and they can do it with one person in isolation, because even in isolation that person is affected by a whole lot of people-factors, but also they can do it with whole groups. whereas Fi users tend to suck at groups because it's hard for us to keep track of everyone all at once. it's like a Fe user looks at a spiderweb while Fi users look at the attachment points.
personally i learned a lot of Fe strategies from my mom, who's an ESFJ. i think she's part of why i come off a little Fe. one of the major things i've learned from her is just to
wait. Fi tends to be very reactive, but sometimes that does not have the best impact. it feels like betraying yourself to not act upon witnessing an event that rubs your F wrong, but Fe wisdom shows that biding your time and approaching from the sideline can be much more effective and have much less negative consequences for both you and the situation you're trying to remedy.
my close ENFJ friend is also very cause-effect attentive in terms of people situations. she is very good at understanding what makes people act the way they do, and then using that understanding to work with them. i am like that in a similar way, but mine is less... conscious? like i "feel" others and understand their present being and work with that, digging to the core of who they are. whereas my friend sees everything that has gone into who they are, and then extrapolates to the present based on that. i think this is a very NeFi-FeNi difference, she definitely has very well developed Ni aux. from her, i have learned to take more stock of situations - to watch how people impact one another. i never found people-watching particularly interesting personally, but when i put myself in her frame of mind, it becomes a fascinating push-pull of will and interaction.
another close friend of mine is ESFJ, and she is very other-attentive. she tends to be very interested in what you're doing, where you're going, how you've been, etc. one of the things i've really noticed with her is that she doesn't seem to try to come up with similar scenarios to relate. my native way of empathizing is to relate a similar situation i have been in, but she gets interested in your story without reverting to her own to try to understand yours, and i think that's an important aspect of Fi. Fi, literally
introverting Feeling, is going to try to draw things back to oneself. and while that's awesome for self-understanding, and we can use that later to understand others, in the moment it takes away from the other person's experience. Fi users can learn to
not draw the other person's story into themselves so much - to look for what the story means in terms of the other person more than what the story means in terms of ourselves.
How would Fe work if there were some rift in a group's dynamic?
given the Fe users that i would know, they would usually try to bring the group into consensus, or at least some kind of harmony. ime, NFJs seem to be more interested in "steering" groups in a certain direction, while SFJs seem to be more interested in "protecting" groups. which, really, are sort of both the same thing, but NFJs tend to press ahead and "wayshow" while SFJs tend to stay behind and tend.