As for CEP 2X versions having "nudity", its optional to use those few appearances and in no way mandatory or forced. If you don't like it, simply don't use it.
While true on the player side, the use of CEP can still be a concern if builder teams wish to include underaged members.
(A Teen friendly option might make future use of CEP less complicated in that regard.)
Potential Scenario:
Minor is gifted NWN by parent who chose a game less severe than some of the more modern and explicit games...
Minor Loads game, sees toolset, learns is a fun toy...
Minor Downloads community expansion pack, because many modules and servers use...
Minor browses CEP content, and is exposed to nudity without warning, and parents become understandably upset after discovering what all the giggling is about.
(Currently CEP is an as-is abandoned project, but if future editions are (hopefully) released, it might be a good topic to address in the future.)
I'm going to go out on a limb and say that CEP does not equal Mature in any way. The early published edition of the AD&D sourcebooks had five or six illustrations in the three books that included nudity. Fast forward to 2014—if it wasn’t adult in 1977-79 it certainly doesn’t deserve a mature rating now.
Hehe, yeah, lots of 0e-1e books had topless barbarians, and Deities and Demi-Gods even went full frontal, no less... *70's Spoiler Alert*
The Question there is should the existing nude 3D models for monsters like succubus, centaurs, marillith, and the Sinfar body parts and armor be considered "Teen" or "Mature" by modern rating systems?
Assumedly, if vanilla NWN is TEEN, then 3rd party mods containing actual nudity, such as CEP, would be considered MATURE by most forum standards, and the intimate emotes and more sexually oriented material found in the various social server haksets are ADULTS ONLY ratings.