Maybe there is some slightly different environment that we would still call hydrothermal in which RNA is sufficiently stable.
Fig 5 - drawing parallels between systems of different levels of complexity (from prokaryotes up to civilizations) is interesting, but it is a bit distracting at this point. The abstract promised to talk about RNA World and the origin of life. At this point the article seems to have strayed a long way from this intention. From the origin of life viewpoint, even the simplest of these (the prokaryote) is still very complex. The issue for the origin of life is how to get to a prokaryote. I don't really think that looking at social insects and human societies will help much in understanding the origin of life. The ideas of CCSI and CMIO seem interesting, but they are discussed with the high-level examples (pages 10-11), not with molecular and cellular examples. Probably a lot of this could be simplified. It is only when we get to paragraph 3.1 that we get to the point of the article.