I study such things as samurai, as I take a Japanese class at school. Plus personal knowledge.
You cannot just 'become' a samurai. You are born into a samurai family, and your father samurai would teach you the ways. You spend every waking moment, when not in battle, training and/or working on things such as crafting. You are to follow your Shogun, or you are cast out. Many who are cast out kill themselves in shame, or become bandits as stated above. If you lose a battle, you kill yourself, which would be a problem on Layo with its death rules.
I'm just kind of against Samurai in a multiplayer setting that doesn't have an oriental area. Many play them like fake anime characters, and not like the real thing; they use catchy Japanese catch phrases seen on the anime in romaji. To me, it'd be an abused class, with many uninformed players wanting to be 1337