[CU-Movies] Please explain or discuss Babel re ending of Japanese story?

[jencart at mailstation.com]

WARNING: Don't read any further if you haven't seen Babel yet!

REALLY... DON'T READ THIS IF YOU HAVEN'T SEEN BABEL YET!!

Hello Chambana Movie Viewers Who've Already Seen Babel,

Please respond if you have a clue about the ending of the Japanese story!
The other 3 stories were wrapped up so clearly, but that one left so many 
unanswered questions, and none of the reviews have clarified the ending,
or even mentioned that it was ambiguous.

I'd be very grateful for any thoughts re the following, either emailed just to me, or posted to the 
whole list for discussion.

 1. What was the relationship of the father and daughter?
 2. How did the mother actually die? Suicide? Murder? 
 3. Did the rifle end up in N Africa simply because that's how the author chose to connect the 
four stories together, and it was an innocent gesture on the part of the father? (The road to hell paved with good intentions.) Or were we meant to believe he was trying to get rid of evidence? (Evil begetting evil?)
 4. What did the daughter write in that looooooong letter to the detective?

Thanks,
Jenifer  <jencart at mailstation.com>