Thanks for your suggestion.
This seems like a good as any time to mention that jcsuperstar
is now looking after the Study Group and as such he has a degree of ownership to make changes to the schedule and the way the Study Group is managed.
That said, I'll explain the reasons why discussion topics are currently closed at the end of seven days...
The main reason they're closed is so that the Study Group remains focused on a single discussion item at a time, just like a real Study Group or Book Club. If all topics were left open, it would be little different to any other sub-forum, and the older topics would get replies and bump themselves up over the top of the current ones... meaning the sequence of threads could get out of whack and the 'current' topic could get lost amongst the others.
I made sure in the closure post for the first few weeks that it was clear people could continue discussing certain aspects of interest elsewhere, so they could see the closure wasn't in any way an attempt to stifle discussion. This still remains the case now, even if there is no formal closure post.