The very last thing in your post -- about volcanic and marine CO2 -- grabbed my attention. It flatly contradicts something I found on the US Geological Survey web site on volcanic hazards:
http://volcanoes.usgs.gov/Hazards/What/VolGas/volgas.html (look down the page for the paragraph comparing human and volcanic CO2 emissions). I should get a hold of the reference in your post and see what they say. If the guys in your post are right, then global warming goes out the window.