I gave up on making the kernel emulate right-clicking from the keyboard since
X11 already has all of this built in.
Someone on the
ppc@ list hinted at binding
Pointer_Button3 with xmodmap.
This is basically what I'm using now, to have middle and right mouse buttons through the Apple/flower key and the square 'Enter' key, respectively:
xkbset exp =m
xmodmap -e 'keycode 115 = PointerButton2 Pointer_Drag2'
xmodmap -e 'keycode 200 = PointerButton3 Pointer_Drag3'
No more having to use a USB mouse.