How does having Fe vs Fi impact a person's life?
I will speak primarily of those with that as a strong function, so feelers.
Fe in an FJ gives them others-awareness and social awareness. They are typically good at finding the right words, adjusting their argument to fit the audience, considering the feelings of others involved, and in knowing how to express their own feelings on the spot. The cost is that they can confuse their identity with their social role and with what others need from them, and when those things are gone, they may need time to readjust and find themselves. ("I am Tommy's parent... Tommy is in college... who am I now?" "What am I now that I have no kids at home? Now that my boss no longer needs me?") Some of them have strong opinions about everything and others over-invest in others's opinions and may not know what theirs are as separate from them; they live up to Jung's assertion that "everyone says this must be good, so I see it as good art" and have to realize "I hate it tho."
For TP types, there is less of this happening; but they may over-focus on what others deem valuable and adjust to that in smaller ways. Like an ESTP not processing a breakup emotionally so much as they immediately find a sexy replacement for their former partner.
Fi in an FP type gives them strong self-awareness and a need to be in inner alignment at all times. They pay attention to how they feel at any given moment and that drives their opinions about whatever they are interacting with -- person, situation, etc. It takes time to fully name and process their feelings, so they have to pull away to do it in private, and won't articulate it until later, if at all. The cost is that they have to self-insert to understand others and/or are less aware of others' feelings, since they are not mirroring or feeling what others are feeling. Their feelings may be the opposite of everyone in the room and their insistence on being "authentic" may cause conflict. Some of them are so wrapped up in what they feel and think, they forget to remember that others are affected by their words and/or that asserting themselves constantly is not necessarily situationally-appropriate. Since they think anything they don't care about is irrelevant, it can be hard for them to respect what others care about without deeming it dumb or hard to understand (why would you even care about that?).
For TJ types, this can come across even stronger, combined with "that's irrational, why would you even be considering it?" thinking. They are less attuned to the importance of emotions, so less attuned to other people having them and less aware of how their words may be received. Low Fi cares a lot, it just can't articulate that easily in anything other than actions, gifts, or by being a provider. So, if you have a highly emotional feeler child and a very logical ETJ parent, there is a mismatch between what TJ can offer (support, guidance, problem-solving, financial stability) and what feeler needs (emotional talks, comfort, external warmth).
I would say the biggest impact is that others know how Fe's feel about them in a warm context; they easily say what they feel toward you, if it is positive (and if it's not, you also feel it, because they know how to make sure you get the message). Others may not know how a Fi feels, because if they are Fe, they are looking for mirroring and external words and reassurances and "where do we stand," and Fi is just... being there. The presence is often enough for them, and they may feel awkward doing the "warm, gushy stuff." It's more like a Fi to feel sorry for your loss, and go away, and 2 days later, give you a present they made to help you through your hard time, because the act of "I thought about you for six hours while I made you this" was a gift of love. It felt like a deeper gesture and more meaningful, because they could not sit on the couch with you and cry, and were not sure what you wanted or needed from them. Fe's can feel unfulfilled by this, since it's not what they would give or need, and Fi's can feel overwhelmed by a Fe's constant checking up on them and "are you okay, do you want to talk?"
So, in the end, the biggest impact is to realize -- not everyone is like me or treats emotions the same way or gives me what I need, so I need to be aware of what others need and how I am coming across to them, and ask for my needs to be met, while meeting theirs as best I can.
