Thanks for sharing these thoughts! I plan to eventually address these data sets and discuss the the future models in more detail, but at a glance the first thing that I notice is that the paper is looking at deep ocean temperatures. This does not necessarily reflect the trends of atmospheric temperature or surface ocean waters. It is hard to see a time scale of decades on those graphs, but on more recent time scales the temperatures of surface ocean water seems to be mostly increasing.
Cold water from melting land ice is more dense and stratifies at the bottom of the ocean. This may be one factor contributing to the decrease in deep ocean temperatures since the end of the last ice age. While in the short-term (centuries) we seem to be in a warming trend, in the longer-term another ice-age is inevitable. Escape from that ice age also seems inevitable, as the orbital cycles of the earth will eventually thaw things out (10,000s of years).
I appreciate the conversation to stimulate my thinking on Part 3 of this series!
I invite you to follow the link to the WUWT site, as not only this paper, but numerous peer reviewed papers dealing with every aspect of climate are there, from every perspective.
The particulars you mention in your reply are discussed in this paper, as ocean upwelling cools the surface of the sea, and then sucks heat from the atmosphere, as water is much more dense than air, and holds a lot more heat.
Thanks for providing a vector for this discussion, particularly where data is welcome, as the complexity of the science leaves many questions that can be too easily glossed over, as the eyes glaze over.