There’s no argument from me on any of that or the contents of your Chp 1.
I’ve not had much time to think about it but, on first pass, your basic thesis rings true. Research on meditation (and later psychedelics) and the Default Network System provide recent support, right?
My preoccupation is the role of cooperation in human evolution and, goaded by Dawkins, I’d started putting a book up online until Wilson & Sober’s, Unto Others came along and did what I was working on with a lot more street cred letting me off the hook.
It’s quite possible that the role of religion is over-determined since evolution tends to pile on and utilize whatever’s there in multiple ways. A core theory of mine is that we evolved in lethal competition with other groups in tribal warfare during which the best cooperators won. If religion, also, binds the group together then it would strengthen in-group empathy as well adding additional selective pressure.
Here’s a link to half of my workup of that. The other half is in process.