Wow, yeah. I feel like I'd need a few days with a highlighter and a photocopier to really understand how that all applies to the passages in question. As you suggest, the author doesn't really describe his methodology or paper structure, and so it's harder to follow than it should be. It feels like a string of related observations, followed by application to a few texts.

The methodology generally seems to be about analysing the mathematical structure of the texts, drawing observations from these to establish 'norms' for the structure of the texts, and then analysing all variations to discern any intended meaning.

But I may very well just be stating the obvious to you there! People have a habit of seeing order where there is none, so you'd have to really get down to the guts of their observations in at least one particular text if you were to really determine how valid they might be.