I heard him on the radio with Savage tonight for a few minutes. He sounds like he is no dummy. He thinks the major new moon powerful tides and pressure on the earth can be correlated to major earthquakes. The big one in Alaska in 1964 (?) and a few others he mentioned.
I think we really have no idea how much force the moon exerts on the earth when they get a lot closer.
What would really seem to matter is how close to slipping a particular fault already is. As tidal stresses peak if the fault threshold is higher, nothing happens. If it is lower something happens...
I think it's easy to calculate the forces, hard to predict the consequences.