Feif Un-
I also don’t agree with myfriend. A gadol once told me that being in chinuch is like being a neurosurgeon with more responsibility. If a neurosurgeon make a mistake C”V the patients life can be lost, if a mechanech makes a mistake C”V not only can that talmid be lost but also all future generations.
Just like before doing any surgery a doctor will get a second and third opinion and discuss the procedure with the patient and family, how much more so a mechanech should first discuss the “surgery” with other mechanchim and the parents.
I’m not sure how much I can help you with the letter but I remember being told that one should emphasize more on the pain being felt than on attacking the one who caused it.
Again, I wish you the best of luck.