I starting off unimpressed that Shouma was blaming himself for something the Takakura kids had absolutely no part in; but I suppose they're been ostracised so much by others, that they've grown bitter. If the boys still love their parents, they probably can't wholeheartedly condemn their crimes, and feel guilt because of that.
I can't imagine Yuri is a heamaphrodite, its unnecessary and too crude for this kind of anime. 'something wrong with your body' is probably just a figure of speech for lesbo.