I agree with most of it, but the detention thing needs some clarification. If my son didn't return from school at the usual time I would go into panic mode (he has special needs), not that he has ever had detention or behaved in a manner that would require such a punishment... yet.
My child had special needs and was continually in trouble. The school did however always ensure we were informed. This was a number of years ago before all this lefty PC cr*p came in, I see no reason why this should not continue.