Hi, Eric. I decided to draw schemes for functions in your module org-collector.el. And started from org-read-prop. Please, check my pdf file - my questions are marked with green. If there are no attachments allowed in the mailing list, you can get it here:

http://live-wtr.ru/org/org-collector.pdf

Can you explain, which function is called, when the user clicks C-c C-c on the line with #+BEGIN: propview? It's almost impossible to understand the complicated code of other programmer without a scheme. Did you see, how many questions emerged after I schematized just one simple function. 

org-dblock-write:propview seems to be really hard.