In a duel or a skirmish, the Center stance seems fairly straightforward: you give up your action one round in order to get a few benefits on the next round (chiefly, +1k1+Void to a roll).
Outside of combat, the whole "giving up your action" part isn't really a penalty. Does everyone take the time to assume Center stance before doing basically anything? It seems it would be fairly silly to claim my courtier gets a whole extra die bonus to delivering cutting remarks because of his stance, and there are somewhat valid game-fiction reasons for making it impractical to use Center stance in a conversation.
But can my shugenja go into Center stance the turn before she tries to cast a spell? Can my Kitsuki Investigator take Center stance just before he scans a room for clues? Can my ninja enter Center stance as she prepares to sneak past a group of guards?
I'll admit the only one of these I have a practical concern with is the shugenja example - most of the others can be answered with "No, stances are only for combat" without it breaking too many things. But shugenja can cast spells in an identical manner both in and out of a skirmish; how can it be that having an angry ronin swinging a katana at your face makes it easier to focus your mind or whatever and get +1k1+Void on your casting roll? And then I thought: but if shugenja can do it out of combat, why can't anyone else? And it all unrolls from there.