I've been chatting with another user offline about this, and I responded as below.
I think I might approach it a bit differently.
Instead of hacking together a child theme to try to get it to loop through - I might write a custom section that allows me to pull the content of a page/post. This would allow me to use any of the page/post editing tools to generate the content, but still follow Pagelines convention regarding section placement and canonical CSS references.
I don't want to break PageLines convention, but the current "contentbox" or standardized "sections" don't allow for free form design and development of the page. This causes a problem mainly with regards to full-width CSS declarations, the subject of which I'm about to create another post about.