There is only one war crime.Losing.
Well, not all of them had a choice, they were probably forced into the military or their families would have been hurt. They were also following orders of their government, which is what any military does. I dislike any military, and do not really have sympathy for those who go out there and fight a war to "protect their country", because they are protecting something that does not exist. Countries are imaginary.
None at all. Still don't for Japs in general.
Both sides of a battle should always be mourned, they are human just like us, even if they tried to kill our countrymen.