Agreed, Kinzo wouldn't really care...
. He's kind of stuck in loony-land.
Natsuhi's the one you have to worry about, trust me XD. (even Krauss seems to think he's a pretty good kid)
And no, we don't know what his past was like yet. I'm guessing that'll be covered in EP 6, maybe 7 if we're not as lucky XD.