I am writing now from KMail in KDE 2, on XFree86

Yup, I can start KDE2 now. My problem was embarrassingly simple. 
Instructions which I had on hand, and in the KDE docs, applied to version 3.x 
of XFree86. I had upgraded to XFree86 4.1.0. And all of the config stuff left 
over from the old X was left in place. So I was editing the wrong config. I 
put "startkde" in THIS file...

/etc/X11/xinit/xinitrc

...and and KDE would start.  

I haven't tried KDM yet, but I expect that that either works, or that I can 
figure it out. I mostly wanted KDE to work so that I would stand a chance of 
getting my wife and son to take an interest. The CLI impressed them not at 
all, alas.

Thanks to all.

Gan Starling
Kalamazoo MI USA