Did you uninstall KDE 4, after installing 3.5? I did that on a version of Linux (I forget the flavor...) and it worked. I installed 3.5 first and then uninstalled the 4.0. Another solution to disrupt the KDE 4 and get KDE 3.5 might be to install just the Gnome base and boot to it, by choosing a different desktop manager at login. Then uninstall all the KDE 4, reinstall KDE 3.5 and switch desktop managers again. Set KDE to default when the system works the way you like it.
I agree with you on the mess they made of KDE 4. It is awful. Some flavors of Linux are porting new installations with KDE 3.5 specifically.
I hope this can be of some help. Keep trying you will get Linux to play nice with you, it is very flexible, not rigid like other OSs that have restrictive licenses.