I looked through the posts.
Explanation of the issue: the userspace implementation of OpenGL for Xorg, called GLX,does not work, maybe it isn't loaded. From what I see, /usr/lib/nvidia/xorg/libglx.so is no longer included in nvidia-utils package, the new name for it is probably libglxserver_nvidia.so
Did you have any lines with (EE) in Xorg.0.log?
Do you see if this log says, if libglxserver_nvidia.so was loaded correctly?
Wouldn't hurt to check, if nvidia kernel module is loaded: lsmod | grep nvidia
Maybe reinstallation of nvidia-utils package could help, although I am pretty sure this was done already when you removed and added nVidia driver again.
Feel free to PM me, whenever you give it another go, even if it's half a year from now :) I'll do my best to provide you some advice.
('nv' is an old driver for old nVidia cards, you shouldn't look in that direction, it's normal that it doesn't load, if nvidia driver does)