Here is the solution I came up with:
find /home/$theuser -mount ! -fstype nfs4 ! -fstype nfs -type d -maxdepth 1 -Olevel 3 -exec chmod o-rwx {} \; The negated fstype options solved one or two of my problems. The -maxdepth 1 solved the other (speed).
I'm not sure if -Olevel 3 is needed or optimal. For short tests, it runs faster without that optimization.
It may be possible to combine the two -fstype options. If anyone knows, please edit this answer.