1. How many average- non slave-owning- Confederates attended a Southern church regularly prior to 1860? How many were fanantics about their church? Without this number- which may surprise many, I'm guessing- his argument doesn't mean much.
2. He did not present any words from non slave-owners who fought for the Confederacy. He cherry-picked public documents to match his own modern perceptions. There are published Southern documents- newpapers- political references that contradict the ones he presented. It was not a 100% one-sided line of thought. Southerners all had different goals and ideas, they were not machines following certain politicians and churches with blinders on.
3. Not very indepth for a historian.