> 1. man wsmuxctl will probably offer a way to do this (can't say I have though)

I ran
wsmuxctl -f /dev/wsmouse -r wsmouse0

and the touchpad was disabled.  Very pleased.  You have to go through so 
many clicks and a restart in Windows.

> 2. do you have
>
>         Option      "ZAxisMapping" "4 5"

No.  Still can't use the scroll wheel.

> 3. I'm out of ideas for this one.  :)

But now I can't disable the screen saver at all--the USB mouse does not 
do itk; I have to use the keyboard.

Thanks,
Yasir