Some more NN theorizing:
I believe it was in GP that Bob talked about dreams and shades making pockets in the NN. I had intended to mention Agatha Hathorne's pocket in the NN in my last post but forgot, and you beat me to it elsewhere.
It's interesting that Lea can walk into Agatha Hathorne's NN pocket from elsewhere on the NN side of things...*
So thinking in terms of Chicago and the NN, there are probably multiple dimensions of the NN that are overlayed over the Mortal plane (I prefer that term over RL)
- There is the plane that Harry cruised around during the beginning of GS,
- The plane that Harry cruised around in during the rest of GS that parrallels the Mortal plane close enough that he could see most of what was transpiring in it, but most mortals couldn't percieve back in the other direction (I'll call this the GS plane).
- I suspect most of "Heaven's" crew normally typically operate on a seperate plane that Uriel took Harry too at the end of GS. One that even the "ghostly attuned" can't percieve
- Then there are the pocket planes that can be overlayed between that GS plane and the Mortal Plane that are shaped from the will of certain mortals or mortal shades like the shade of Agatha Hathorn.
- Planes that can be brought to be by supernatural beings
- Mab and Titania's "over chicago" battle royalle plane specifically mapped the topography of the land it overlayed.
- Various "Ways" and portions of Fae and other NN realms (I.E. Hades, down below, olympia, whatever) that topographically connect to the mortal realm because of similar natures. This seems to mostly** be a seperate set from all the above.
- I suspect there are parallel dimensions that split off based off of mortal decisions and such. These dimensions are things that beings like Uriel have enough oomph to have domain over as I mentioned in my OP.
- Interestingly, judging off of what Lea mentioned in GS about records of human experiences being stored in places other than their wetware, plus some of Harry's experiences with Lash, I suspect there are levels of existance where these "records" exist, and I highly suspect that beings of angelic nature exist on/have access to them.
Interestingly, sufficiently powerful beings seem to be able to shape a preexisting portion of the NN to their desires, not unlike a construction crew can shape a hillside for a subdivision. Remember Evil Bob's Normandy, and Lea's garden.
Harry's "Nevernever" term is a catch all term that refers to all of the above plus more that he might not even be aware of (not unlike his usage of the term "demon").
By the way, it is my opinion that Harry's trip to the grey fuzzy areas of life and death have given him a certain affinity to these extra planar portions of the NN in such a way that he can possibly visit them or otherwise capitalize on (or be capitalized on from muahahaha) them in ways that other mortals can't.
Edit: Also, tying back to the earlier discussion of 1:1 vs n:n topography, I suspect that numbers of these "planes" could be accessed with a "gateway" from the same spot on the Mortal plane with the proper intent and perspective.
*Lea exists on more than one plane though, as evidenced by her being corporeal to Ghostly Harry
**emphasis on "mostly"