All your concerns stem from not jumping in.
As stated - Nehrim uses Oblivion resources (Oblivion BSA for meshes, sounds, textures, and misc) ... this means that for the vanilla resources used it is vanilla. Nehrim also has its own BSA archives too. Mostly it looks vanilla with a lot of unique models throughout the game.
Just like with Oblivion you can't install QTPIII prior to the game itself. But frankly I'm so over QTPIII - there are a few other texture packs I consider just as good, It is as if everyone reads dev's old TOTO page and says "OK QTPIII on my list" without ever looking at what else may be available.
If you want to mod Nehrim then first decide if you want both a Nehrim and Oblivion game playable - if you do investigate the tool mTES4 Manager. If you don't and only want Nehrim then install Oblivion then immediately Install Nehrim. Doing this will clarify most things as you will see it will create a different install path.and data folder. If you later get nostalgic for Oblivion and want to play it again you can still use mTES4 Manager later - it is just easier to set all up prior to adding mods to either game.
Then all that I wrote in the first post will start to make sense. If you look you will see that although it has a different install path it still uses the same registry settings of Oblivion, same save game folder, and same AppData folder. Knowing these are important to knowing how to use the existing tools (CS, OBMM, Wrye Bash, TES4edit, Gecko, etc).
Psymon,
I installed Oblivion, Official Patch for it, Nehrim, official patch for it, then some Nehri-compatible mods (including QTP3) I found description in the first posts of this thread. Until now, everything is OK. No CTDs!
I am a mod-user, not a mod maker/mod designer. I tend to skip the posts instructing how to mod Oblivion or Nehrim or any other game. But I read the 3rd post on this thread listing the mods that are Nehrim-compatible.
Regarding QTP3, I just want to give my opinion. But before this: I know this is NOT the right thread to give this opinion. But considering you touched the theme, here it goes:
I know TOTO page is old, not updated web site. But if everyone reads it and have this same idea like "QTP3 is a must have, I just can't play Oblivion without it" (and I totally agree with you here, I also had - and still have - this same idea) is just because we beginners in the world of Oblivion game can't find another good page with great Texture Pack Mods, like TOTO.
You see: TOTO page is not update anymore. And yet so, every newbie (me included, why not?) comes to the Bethesda official forum asking for helps/hints regarding QTP3.
Why is that? Because TOTO page is old, I agree, but there aren't many pages with information about Oblivion texture packs. Actually, there aren't many pages with information about texture packs newer than QTP3. Even newer texture packs we can find out there are optimized or Pyffied versions of the good ol' QTP3. If there are dozens of great mods (vampire mods, weapons mods, magic mods, quest mods, ....), there are not many good Texture packs for Oblivion. Or if they exist, they're hard to find.
Or then QTP3 has a great propaganda, an unbeatable word-of-mouth.
PS: I gladly accept suggestions (aka links) for texture packs other than QTP3. It seems QTP3 is alone in its category.
Thank you!
Henrique