When netbooting Roswell /usr is not mounted before kudzu is involked in the init scripts. It can be worked around but it's not particularly graceful. Perhaps using a static version of kudzu in /sbin or rearranging the init scripts so that an NFS /usr is mounted first.
IMHO, a static build of kudzu in /sbin is probably the best way to go.
kudzu calls other things for configuration that aren't on the root partition... (mouseconfig, Xconfigurator, etc.)