IS it possible to move the content models around to different folders without screwing anything up? 

You can normally move the content of libraries/character/prop etc without much trouble. Do NOT move geometries or textures around and dont move the !Daz folder . Some props have the obj in the props folder, those you cant move without editing the prop file.

What do you mean by "moving content around"?  Are you trying to put things in a different runtime, or do you want your geometries in another spot?  The former, you should be fine, so long as you link the runtime in your library.  The latter could cause you a lot of problems, including having to manually locate figures every time you try to load them from the library.

Using something like 3Pdo, you have a good chance of making it work as long as you only move things within major folders... like from one folder to another in the Characters folder. If you move geometries or textures, it's broken for sure.

I think a better solution is PzDB, which takes a database approach and allows you to create your own groups without actually moving anything. The downside of this is, if you want it to load things automatically, you have to use pRPC (which is installed with it) but THAT doesn't play will with some of Poser's functions, so I wind up turning it off and on a lot.

It's all in what you prefer. Look at both programs. I have a feeling one or the other will solve at least your major issues.

Almost Anything can be moved some way open a cr2 as a text doc in editpad or whatever and search for obj or image reference if those lines are edited to reflect the directory changes of the geometries and textures the altered Poser object should Open
This applies to mc6 cm2 pp2 hr2 probably mt5's there's Poser files and then there's resource files meshes and image maps

I understand about the geometries and textures. But I was wondering if there was anything pointing towards the actual .cr2/.pp2 file. Can I just drag that to some other folder. I'm trying to rearange my library in a more cohesive order.

Within each of the Library substructures yes
Also mostly you can rename pz2 to cm2 and some of those crossover

 Oh, so you're trying to re-organize your runtime?  Those should be fine.  I don't see why moving them should be an issue at all.  I do it all the time :)

Okay, so I want to create, say, a Victoria 4 folder, with sub-folders for clothes, hair, mods, etc... and sub-sub folders for each clothing set, hair style, etc...Now can I just create a Libraries/V4/hair folder, or does it HAVE to be in Libraries/Hair?

That isn't possible in Poser you could have a V4 Runtime with sets of v4 based cr2"s in the character library  a set up for Hair etc.

It has to be Libraries/Hair, otherwise Poser won't see it.

What you can do, is make a new folder titled "V4" and have the Runtime (Runtime/Libraries/Hair etc.) setup in that folder, and add it to Poser.