(II) Loading /usr/lib/xorg/modules/extensions//libglx.so
dlopen: /usr/lib/xorg/modules/extensions//libglx.so: cannot enable executable st
ack as shared object requires: Permission denied
(EE) Failed to load /usr/lib/xorg/modules/extensions//libglx.so
So far, this thread reminds me of the joke about the blonde who lost her contact lens. She was crawling around on the floor looking for it when a man comes up to her and says: "what are you looking for? Can I help you?"
She looks up and says: "oh yes! I lost my contact lens over there (points across the room), and I'm hunting for it."
"Well, if you lost it over there, why are you looking over here?"
"The light is better over here."
Point is this. The reason you can't get the nVidia driver to run is shown quite clearly in your log file. The driver is failing to load libraries that it needs in order to run. You have a permissions problem associated with /usr/lib/xorg/modules/extensions.
What is that permissions problem? I don't know. But take a look at the directory /usr/lib/xorg and all its subdirectories, and you'll find your problem there someplace. Might be that the libraries haven't been set as executable. Might be that X doesn't have permission to execute what is in that directory. Might be a bad symlink. I can't tell from here, but that is where your problem is.