I'm glad you found a better cursor, but it is too bad that the tip about increasing the size does not work.
I'm sorry, but I don't know the gnome tools very well, because I use the light-weight flavours Lubuntu with LXDE and Xubuntu with XFCE most of the time. I hope someone who uses gnome and or Unity can chip in and help you.
What about the solution to simply have lower resolution than the default one (which is the highest)? Then everything will be bigger. You can easily change the resolution with the terminal command xrandr. In my case:
I can 'downgrade' the resolution from 1920x1080 to 1440x900 or 1280x800 (and keep the wide-screen) with the following commands
Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 16384 x 16384
DVI-I-0 disconnected (normal left inverted right x axis y axis)
VGA-0 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 530mm x 300mm
800x600 60.3 56.2
DVI-I-1 disconnected (normal left inverted right x axis y axis)
HDMI-0 disconnected (normal left inverted right x axis y axis)
and reset it with
xrandr -s 1440x900
xrandr -s 1280x800
You can make one-letter aliases for a couple of resolutions and easily switch depending on the application program you run, for example
xrandr -s 1920x1080
Use the relevant resolutions for your screen and enter those lines into your ~/.cshrc file (near the other aliases) if you like it.
alias c='xrandr -s 1280x800' # custom resolution
alias h='xrandr -s 1920x1080' # high resolution