Regarding  "I've observed that @property graded was False even is has_score was True":
With graded as a property, as you can see at https://gist.github.com/anonymous/11368589, graded is False, but has_score is True. Progress page works fine: problem or practice scores are shown depending on subsection graded value. Probably it is something with debug info. @cpennington what you think? It can't be verified with LTI, as LTI has no "debug info" panel.