Yes, I would agree that diet is far more important. Steady cardio is "very" effective though. I'm not even going to bother reading that PTC article as I'm not a fan of his preaching. As for steady cardio to remove muscle: You actually need to be doing high intensity cardio for a very long period of time for your body to start breaking down muscle as a source of energy. Far more intense and prolonged then most people are capable of.
I agree that this could turn into a huge argument or pissing contest. To be perfectly honest I couldn't be stuffed going there.
I think that lower BMR may make it harder to lose weight as you have less to lose.
And agreed, Tabata is a great way to train, though not all the time. It needs to be thrown in as a mix up to keep the body guessing.
End of rant