Re: Can't enable XGL
The second problem I mentioned of corrupted characters when installing the nVidia drivers has at least been found what is causing the problem.
By accident and a lot of reading online, I found that running the nVidia installer with --ui=none uses the command line to install the driver. Therefore that particular problem was caused with ncurses and not the installer itself.
The main problem of the high CPU usage for X+Compiz and being unable to get Xgl to run is still unsolved.