Where I differ from you in my take on this is that I also weigh what isn't there. He doesn't provide any form of alternate explanation. Nowhere does he say anything that comes close to "I don't believe that affirmations work this way" or anything of the like. I also don't agree that his hedges clarify anything, rather they muddy the waters.
He presents a thesis, presents other people's arguments for that thesis, presents no arguments against, and then explains that he lives his life in a way consistent with believing in that thesis. The hedges fill one function: to make it harder to argue against him. If the arguments aren't his, the chapter stands even if the arguments fall.
To me, that is basically arguing for the thesis, but in a roundabout and quite defensive way. What other point would you say that that chapter conveys?
There is also the possible half point between atheism and agnosticism, where people self identify as atheism but will act according to some religious concept because they view it as important to their lives. To me it indicate strongly that beliefs, any beliefs, sits along a spectrum. A person can live their life in a way consistent with believing in something, either because they believe in it, or they don't know, or that they don't believe in it but still behave in that way because of a reason or an other.
To me, the quotes you give seems aimed at people with preexisting beliefs in multiple universes or quantum woo, and he seems to want to convince people that affirmations can be viewed as perfectly reasonable in their existing belief systems. This does not mean that he believes what they believe.