Windows are relatively motionless most of the time so transparency effects can be cached or are burdensome only when motion occurs, Genie effects take a second to occur so disabling it will only help you during the brief moment you minimize the window or undock it. If you want to speed up your OS X Finder experience, use List view as little as possible. Defrag your hard drive. And run one of the prebinding utilities if you haven't already. I am running a beige G3 233MHz with 225MB of memory.
Programs run at a very acceptable speed.
OmniWeb is plenty fast. Faster than any browser I have used under OS9. The only slowness that bothers me is program launching which is slow, very slow. Classic environment is absolutely glacial in starting up. I would rather that Apple put the effort into adding the missing bits.