This is a very good description, especially from an outside point of view. I hope I can help provide an "inside-out" view, bouncing off of your input.
Ni-dom spin perspectives a lot. Things become what they want it to become. Sometimes its insightful & illuminates a better way to interpret reality, but other times it's disturbingly delusional & extremely self-serving (ie. taking no responsibility for bad behavior by justifying it via perspective shift).
One should understand it's likely not even a "spin", but it certainly seems so to an outside perspective. A theme I try to make clear to non-Ni types is that Ni isn't
that fuzzy, it just seems so because it doesn't translate into concrete definitions that well. The Ni "building blocks" are just as fundamentally rigid as Si or Ti or Fi "building blocks", and other types sense this in terms of our stubbornness.
The "spin" observation derives from the fact that while the building blocks are fixed, the particular
questions are not. Keep dropping electrons onto an atom, and they don't just fill the inner s orbitals: they eventually start filling p, d, f orbitals, each of which has a very different qualitative shape. The equations (Ni building blocks, in this analogy) are the same, but the resulting answers tend to differ by a lot, even though from a more "Si" perspective, nothing has really changed: we're just putting identical electrons on an atom, so why should subsequent ones behave any differently?
Ni doms tend to change their answers based on the question being asked. One of the more interesting things that Nardi notes in his book as that Ni doms seem to excel at answering a
single question. The single question sets the parameters and boundary conditions for that particular case, and Ni "solves" for that case.
The selfishness comes from the question being asked is very often, "How do I get what I want?" Change the parameters, but the question stays the same, so it looks like opportunistic angling, and hence, "spin." The way to deal with this is to change the question. Here's a sneaky way: "Are you sure that's what you want?"
They don't tend to easily trust other's ideas. From a Fi-dom perspective, I don't easily adopt others' valuations & there's like a knee-jerk reaction to keep them uncorrupted from external things. It's a similar thing (to me) with Ni-dom, except it's ideas/perspectives/interpretations. This often comes off as unfairly dismissive to others' ideas or as having tunnel vision. Yet, unlike a Ji-dom, there is little association of the idea with themselves, which is where the arrogant vibe many get from them comes into play. It's as if they just see their interpretation or idea as reality.
You have some very good observations, here. I should note, however, that you're treating Ni-understandings as if they were Fi-valuations. Mature Fi types understand that you need to accept others' valuations as valid for themselves, with the exception of a select few values that should be universal. That isn't what a mature Ni should become at all.
Ni is more like Si, in that both should converge on a mostly-shared worldview that is "true." Si highly prioritizes social conformity, even for STJs. The difference with Ni is the sheer
difficulty of sharing one's own worldview. You ask us
why thus and such is true, and we end up looking stupid with a complete loss for words, or the words jumble out and don't make any sense to you at all, or we pontificate on a general thesis, saying things that appear to be obvious-but-irrelevant or clever-but-oh-so-self-serving (through your Fi lens).
Why do Ni doms so easily dismiss others' opinions and points of view? Because they often dismiss ours, first, since we couldn't really "prove" our point in their terms. We don't "trust" others' ideas because the connection by which we'd actually share ideas has not been made, period. It doesn't
always happen this way, of course; I'm just pointing out the dynamic of how it occurs when it occurs.
...
On average, I don't find Ni-dom openly analytical though. There's almost a dismissal of it as "too obvious". Trying to engage an INJ in person in an intellectual discussion for its own sake doesn't seem to get anywhere. ISJs are easy in this way....they're especially easy to impress, or annoy enough to engage anyway. ENJs are easy too....they love to spout opinions, being J-dom. But INJs seem to just write this off as noise. They seem more interested in analyzing trends & how things will develop in the future, as well as what something currently happening means for the long run. It's waaaaaaaay less whimsical & playful than an NP. It has a practicality to it that would shame an SJ, but more big-picture & future-oriented. Often times it resembles paranoia, but at best, it's a good head start in preparing for what you need to be in order to deal with some pending reality or an interpretation that clarifies a formerly fuzzy idea of reality.
Very good observations, here, especially with respect to noticing how Ni, which seems so fuzzy, can clarify fuzziness. This is what Ni doms aim for. Note, however, that this is usually the result of a huge amount of work. Newton, for example, had to
invent calculus just to "clarify" his ideas about physics and gravity in particular.
We're not "openly analytical" as you put it, but when you get that clarifying answer, do not doubt there was a lot of analysis put into it.
As you can probably tell from this, Ni appears much narrower than Ne to me, but I suppose its deeper. Ne wants to play with all the patterns, all the contexts. Ne gorges itself on ideas & interpretations & perspectives. Ni seems to focus on likelihoods, but without discounting the unexpected - how the pattern is likely to shift, how the current context is likely to change into something else, what something really is at core, etc. Apparently, there are archetypes from the unconscious mind - a sort of innate library of how reality generally works in the most fundamental sense - that is sourcing these ideas, but I don't know about that end of it so much. I think introverts generally explore ideas of the unconscious via imagination, or at least, that's how I see it/experience it myself.
Very good, @bold. Those are the Ni building blocks. Note how there are no words for it. One minor difference, from my perspective: it isn't "what something really is at core", it's "how these things really behave at core". The particular "thing" doesn't matter.
Ni is associated with a meditative state of thinking, and I see this as observable in them. Ask them a question, and they pause in a way that looks like a meditative state. Again, many introverts do this, but the type of question can clue you into it. If it's an idea question, an NP gets 500 lightbulbs over their head, and again, you can witness this in their demeanor & often quick response. If that NP is a Ji-dom and you ask them something which requires a judgement, then you get a pause also, but it's less meditative (it's more like wheels churning, ideas being connected into something that makes sense, the connections being ordered & fit into a bigger idea, consistency of it all being tested, etc). Si-dom look like they're reviewing (the way your face looks when you scan a book for a previously read section) or comparing notes of the past to what is at hand.
Good answer to the OP, here. Look for that meditative state when you ask a question.
IMO, Ni seems very narrow, as it often discounts other likely possibilities to focus on developing one. The typical Ni-dom offers no explanation for their idea either. There is often no line of reasoning to back anything up. This is key to knowing you're dealing with a dominant perceiver. They just "see" things as they are (or as the interpret them subjectively), and they expect others to simply accept it as a fact, as if it's a concrete object in front of your face. When people don't, they pout like babies (INFJs) or dismiss everyone else as stupid (INTJs). This focus can be beneficial in weeding out useless paths others might explore, but it can also be detrimental when the person, unaware of their own bias, clings to an idea that is more flattering or beneficial to themselves, not necessarily more REAL or more accurate of an interpretation.
Ni is "narrow" because it's only answering one question at a time. It is the
question that both provides focus and excludes possibilities.
Mature Ni often asks a meta-question, namely, "Am I asking the right question?"
Even less mature Ni do this to a large degree, usually by walking away from a problem after working on it without solving it. After we stop thinking about the problem, we get to "reset" the question, and come back to it a while later with an ever-so-slightly different question, and it's the
different question that provides the instant "a-ha" style answer.
They also seek to regulate reality to their ideas, whether passively (sometimes even unaware of it themselves; ie. self-fulfilling prophecies) or intentionally. The intentional method can amount to only exposing themselves to realities which align with their views; so they deny those which don't, or cause actual change to make it fit their view, or they simply put a strange spin on it to make it align. This can range from actual situations to factual knowledge. The passive method seems to be acting or provoking others to act so as to indirectly affect events, and then what they expected actually happens. Obviously, there's some Je going on here too, especially when they act in some way. They often don't see their own hand in it though, which to me, as a Fi-dom, comes across as disturbingly void of personal responsibility.
Good observations, here. Though I would suggest that there isn't so much a passive or intentional attempt to
regulate reality. Rather, it is
opportunism. The same way an athlete keeps ready, waiting for the ball to come his way and react appropriately, an Ni-dom keeps an eye on the inner dynamics (the Ni building blocks), and acts when the dynamics are favorable.
Such opportunism makes people think INTJs are great strategists, or that INFJs are great manipulators. Obviously, if events worked out to be so favorable to themselves, they must have planned the whole thing, right? No. We only have a vague idea how things will work out. We just wait until they're virtually certain to work out. I bring an umbrella because I know it will rain today. I didn't make it rain. See the difference?
They know a lot more about you than you've told them or that anything tangible could communicate, but they still don't know as much as they think they do. This can be problematic when their idea of you & who you really are conflict. They project stuff onto you a lot - you become some symbol to them of something (in romance, you're often the essence of womanhood or whatever), and all of its associations then become equated with you. It seems like they seek to sum people up quickly, but the healthier ones will take unexpected aspects more in stride & even be amused/entertained by it.
I sense you're talking more about INFJs, here. INTJs are well aware that we don't understand other people as
people. (We do understand them as "objects", at first, but the people-understanding is hard-earned.)
Every now & then, life blind sides them & it hits them harder than most, because they're not used to it, I guess.
No, we're very used to it. We just happen to dislike it very, very much.
It's why we
are prepared, more often than not, because we really hate being unprepared. Even more than boy scouts.
Since, we're INTP bashing

, I will say that INTJs are easier to converse with when it comes to accepting other people's opinions. You can make a statement & they'll accept the main point without interrogating you over every detail. It's so exhausting to talk with an INTP & have to prove every word choice as accurate. They drive me nuts! On the other hand, the sad little masochist that lives within me (and every Fi-dom) likes being driven a bit nuts
sometimes, so INTPs can be more fun in that way. When they disagree, INTJs just smirk or something, and I'd rather have someone just argue with me & give me an opportunity to explain myself thoroughly.
Yeah, we INTJs only want to argue if we think it is worth our time to argue. You have to make the
connection first, idea-wise, to earn the argument, and then you need to not instantly back down when it gets intense. We have two goals when arguing: 1) to learn something new, 2) to learn how to communicate our ideas better. (I can hear several people saying, "No way," even as the INTJs nod their heads in agreement.) Recall that our primary difficulty is communicating our ideas clearly. It is by communicating them clearly that we get others to understand them. And once someone else understands our idea
on our terms, and
then offers criticism that recognizes those terms, we learn something new. But yeah, unless we make that idea-connection with someone else, we can be real dicks if we're not careful.