This is such a moving poem and says so much, just as it is. Here's another perspective. Try the same poem, but everywhere you say "I forgive you for", replace that with "I love you and I understand why you...." What do you think?
Your first point is the most important one: Little Josh did nothing wrong.
Nobody living can ever stop me
As I go walking my freedom highway.
Nobody living can make me turn back:
This land was made for you and me. (Woody Guthrie)