MM,
it is becoming clear to me that even if we're both INFJs, we are quite different. I can see your perspective, yet mine is different. Let's see if we can sort things out.
Okay! This stuff is so fascinating, I can't get enough.
First of all, I don't often have vivid dreams, lucid dreams or anyhow inspirational dreams. They are mostly a completely meaningless, dizzy blur that only mirrors my time awake, if anything. I was interested in dreams when I was younger, and I've had a few recurring dreams which have felt meaningful, and also a few lucid ones. But no matter how much I would want my dreams in general to be more interesting, they are the complete opposite, and I don't really care about them anymore. I think you are assuming too much (as perhaps I do too) that your Ni is everybody's Ni. As the most abstract of the functions, it is probably the hardest one to grasp, to clearly define how it works. "Ni works in mysterious ways", so to speak.

I find it fascinating how it works in you, but much of what you speak of is sadly underdeveloped in myself. I have felt it, but I can't really get to it. More on that later.
* I think each person Ni is definitely different, but I do think there are some way that they "operate" that are similary. Stepping through your Ni is one such operating principle. I lucid dream while sleeping and while waking. The sleeping ones tend to be more inspirational and the waking ones tend to be more insightful. My deep Ni moments do not distinguish between what they give me. They give what they want and I am grateful to recieve. When I was younger I tried to "fish" for what I wanted but have since learned to stay out of it's way. So when this happens what I get is Ni stuff that relates to my relationships, my writing, my path in life, others paths in life, what currents events that I am aware of mean in the archtypal timeline sense, etc. I just let it all come and make note, as you do. Once some "themes" present themselves whether they be inspirational or insightful, I will try make some internal tests to see if I can't get a read on what is being presented to me (Ti). This can only go so far and then I am going to need to step through it. I usually use my Fe. On "first drafts" I am alone and project or summon creatures into the room with me. I am aware that these creatures are not really there but they are necessary for me to step thru using Fe because I must "talk to somebody who isn't me". I often summon friends that I know because their energy is very familiar to me. I then "talk" to them about my insight and two things always happen (well they do now that I have been doing it a while). The first is that when I speak out my inspiration or insight it ALWAYS comes out different than I thought (this is why you do this alone!) so that AFTER I speak I think "interesting" and I note it. This will help my mapping of Ni the next time I do a self monitored meditation. I would not be able to get that map point by being with my Ni. The Ni must flow through me. For example, when I am going to talk to a friend with the intent of "moving" them...yes, the infamous INFJ people helping/horrible manipulation. Anyway, I "rehearse" with imaginary versions of the people I am going to talk to. As I try to express the insight I gleaned from communing with my Ni previously to this person, the Ni insight grows and gets more fleshed out. IMHO this is essentialy if you are ever to develop enough strenght to get you "voice". I believe that the "voice" is the primary mojo of INFJs regardless of what form it takes (writing, advocating, supporting, transforming, etc). The second thing that happens is that my delivery just feels "off". Even though the person in the room isn't actually there, I have still created them with my Ni from a real person I know so I just "know" they would ask me a certain question when I said that but I wouldn't know they would ask that question until I speak out load and THEN I just know they would question this or that in this or that way. I then AUTOMATICALLY answer these questions in a natural way as if we were really dialoguing. This expands my Ni as if it was being "pulled' from me instead of my projecting it. This is considered HIGHLY desirable for INFJ in every book I have ever read on the subject. Many books are very specific about the value of getting extraverted close companions (I recommend ENFPs and ENTPs) to pull things out of the INFJ that will remain hidden and IN THE FIRST Ni-ONLY STAGES OF DEVELOPMENT.
I didn't see the meditation I practice as a way of of "turning off" Ni, but I can see what you mean. The trance, the special Ni-ish state of mind actually does go away. And your point then is that Ni in this position is not living up to its full potential. If we define Ni as merely a great source of inspiration, then the emptiness of meditation is like watching Ni from the outside, which might at the most be relaxing and let you get some bearings. But is that all there is to it? Ni is partly inspiration, but it is also a direct seeing, and I would say that the seeing in meditation is Ni. That is part of what meditation gives me: it makes me see things more clearly, and in that seeing there is a great potential for change. As clearly as I see a tree in front of me, I lets me see my thoughts and impulses
from an outside perspective, the mental state of a person I meet, my own awareness as well as my ego. And behind all these things, there is a great emptiness that cannot be put into words.
* No you definitely do not turn of the Ni and I didn't think you did. When I said this I was referring to states where you aren't consciously aware of it (ie dreams you don't remember, being in the grip of the inferior function, immersing yourself in the inferior function in a relaxing way, etc). I was referring to the possibility that you may feel that at these times the Ni was "off" and therefore that may have made the need to "touch" you Ni in the meditation you are doing. I could be wrong but I think just being with your Ni is absolutely the foundation for an INFJ, but once you know your "signal stream" and know how to get to it consciously at will (which is what that kind of meditation trains you to do) then there comes the question that haunts every INFJ I know (I don't want to speak for you of course) and that is "okay, so now what does it mean and what am I suppossed to do with it?". For me, my Ni gives me a very good "hunch" but I must field test it to see.
Maybe your Ni is primarily inspirational, and mine is more concerned with "insight"? As much inspiration as your Ni seems to give you (*jealous*) meditation could indeed become an obstacle; when you are inspired, your inspirations will need to be expressed, and why wouldn't you do that? I am not that inspired though, and there is nothing I can do about that, except letting go of myself and allow whatever arises to arise.
* My Ni comes in many forms, but all of them require expression at some point in order to develop them. That's why inventors make prototypes. There are things you just won't know until you 'build it". The Ni is not suppossed to stay inside the INFJ. The INFJ is suppossed to eventually develop the Tertiary Ti so it can discern the inspirations/insights/a-has that the INFJ wants to "get more into" and this is with the intention of finally bringing it to the world at some point. It is in the finding of "how" the INFJ would actually do it, that often helps define the "voice".
The thing is that I have really felt "the power" of Ni, the "mana" or whatever you want to call it, and I feel it still every now and then. The strongest thing I've felt is a glimpse of a vision to be communicated to other people, to be expressed primarily through Fe, psychological as well as political. But I cannot do this yet; I am too weak and too much trapped inside my ego, and I *know* that the most direct way to "get to" this vision is the meditation I am practicing. It will take many years, but then I will have access to the power and hopefully be able to do something for the world. And paradoxically, I have to let go of it to get it. This is not imagination; it is (again) a faint but direct seeing that never really goes away, which I can only follow without really knowing where it will lead.
* That's it! That's it! I get these type of Ni impressions/visions also. If the meditation is taking you closer then rock on. At some point however you are going to have to a) see what ya got. you won't know this until you take it (Ni) out of your pocket (conscious mind). When I have the politcal/psychological insights I definitely use my imaginary friend vetting process (often on long walks in quiet areas...super early in the morning or super late at night works best for me). Eventually this brings me to the point where I just "have" to "test" it out on the real people. These are always friendly and intuitive people at first. Going to people who don't understant you or Ni is just a recipe for getting my psyche beat up. Then to friendly peole who don't know me, and on and on and on. Each stage makes the voice on this stronger, fuller and clearer.
So, I am not trying to control my Ni inspiration or anything like that, which of course wouldn't do any good. But it seems that our intuitions have different emphasis. How much do you recognize yourself in what I have described - insight rather than inspiration?