Glad you now have the object libraries properly installed.
If you would like to continue to try and solve the mystery, next step is to make sure you don't have another library enabled (inadvertently) that contains the same problem object or objects. For example, you know one of the objects that was showing up with black textures is the fuel shed from the FSXP3D small airport objects 2.bgl object library file located inside the EZ Scenery LibraryFSXP3D set of libraries. Go into your Scenery library and disable that object library set and see if the fuel shed object (whether textured or black) still shows up or does it disappear.
If the fuel shed disappears, then you know that the object library set that you disabled is the one causing the problem. If it is still there in some form, then you have a duplicate library enabled somewhere. If the problem is a duplicate library, first thing to do is search for any files on your system that have are named small airport objects 2.bgl. Notice that I dropped the FSXP3D. That is because I added the FSXP3D when i converted the original library to indicate it was now converted from FS9 models to FSX models. If you do have a duplicate object, it would most likely be contained in one of the old EZ Scenery Library sets within the file named small airport objects 2.bgl.
Rod