I could definitely see a rogue or monk "ninja" archetype and fighter or cavalier "samurai" archetype. I'd kind of like to see base classes, but I'll settle for nicely done archetypes. It would be nice to see a "shinobi" prestige class for those that wanted to go for a true ninja PC, and maybe a kensai or swordmaster PrC to make for an ultimate samurai swordmaster or wandering martial artist swordmaster. I guess we could expect wu-jen and shugenja archetypes as well and maybe even a sohei archetype. Some martial arts styles would be nice as well.
Just about everything you mentioned above applies to Kaidan classes, except: Shinobi will be archetypes for alchemist, monk, ranger, rogue and sorcerer, with a Ninja prestige class available to all Shinobi classes.
Wu-jen is a word invented by Gary Gygax, yet Japan has many viable wizards from its history/folklore, I don't intend to carry GEG's fake spellcaster. Japan had Onmyoji which best represents a professional full time wizard. Japn had Jugondo which was a hedge wizard, so I'm going to use that for Sorcerer.
Shugenja - this deserves some explanation. Shugendo is a religion. Shugenja is anyone (a child, an NPC commoner) who follows the path of Shugendo. Whereas Yamabushi is a priest of Shugendo.
Christian is to Christianity as Shugenja is to Shugendo. Using shugenja to describe an oriental priest is the wrong term. So I am using Yamabushi as my 'shugenja', and it will be the PF Inquisitor.
Kannushi is a priest of Shinto, so that's Kaidan's cleric.
In Kaidan, Sohei is a variant paladin/anti-paladin and a LN 'paladin' (any lawful).
I intend to fix lots of old RPG mistakes regarding oriental settings with Kaidan.
GP