You base your whole diatribe on the fact the dp told someone in Texas to pack their walls with cellulose. Did dp do this? If so did he know they were in TX? I may be wrong, but I don't recall he did this. So using this as your basis to say that dp cannot be 100% correct all the time is wrong. dp would have to have said "In texas use this insulation" for your point to be valid.
As far as brands go, I know a bit about dp and what he does, from this board, so his recommendation for paint would make more of an impression on me than a random poster saying use behr. If I knew you were a professional painter with x years experience I would listen to you closer for paint advice. I've been on the board long enough to see the specialties of the regular posters.