Thought -- perhaps "unschooled" shugenja should have the option of having no affinity and no deficiency.
Affinities and deficiencies are on the list of mechanical elements I may or may not continue to include. :-) In 4e they're one of the primary methods of distinguishing one shugenja school from the next; if schools have five techniques, that's less necessary. I haven't yet decided one way or another.