Thank you so much for all your research and labor. although I don't know how to help, judging by your spirit and enthusiasm I'm sure you'll get to the bottom of this.
best wishes.
Thanks. Seeing all these files, I believe modding Witcher 3 would be much more easier than Witcher 2. There's everything from grass, trees, water, smoke effect and so on. However, other than tweaking the XML files, we'd need to REDKIT for Witcher 3 to really get started and replace the default textures with better ones like people did with Skyrim. At the moment I don't know how to access those files. They got .W2P file extension, which might correspond with REDKIT, so yea, we'd probably need that to open and modify those files. Or maybe someone has other solutions in the meantime?