Ubuntu 11.10 is built on the premise of the GTK+3 software libraries. Therefore, removing GTK+3 will effectively mean no "ubuntu". What you will be left with is a newer kernel and a few additional slightly upgraded packages.
If you are not interested in backward compatibility etc, then it would be simpler to start from a GTK+2/gnome2 based distro such as Natty and upgrade from that.
Thus, at a minimum - look to installing the 11.10 kernel - either from the mainline or compiling your own.
If the tenor of your question is simply that you don't like the gnome-classic option then personally I would look at similar gnome-2 workflow options such as Cinnamon or excellent panel based options such as LXDE/Lubuntu or XFCE/Xubuntu.
I would also mention MATE that delivers much of the GTK+2 based libraries onto on Ubuntu. If you take this option, you can use questions like how to remove unity to remove the GUI shell without touching the fundamental core of ubuntu.