I stopped when I saw a passage saying “One or more textures in this pack have been created with images from CGTextures.com. These images may not be redistributed by default, please visit www.cgtextures.com for more information.”
Then I found the following passage in their FAQ:
May I use these textures in my Open Source (Creative Commons, GPL, etc) project? No. These textures may not be used in Open-Source projects. The licenses are not compatible. Almost all Open-Source licenses allow redistribution of the materials, and redistribution is not allowed for these textures.