Hi guys, I read and re-read this whole thread again. I admire the knowledge and skills many posters have by the way they discuss about this topic.
What I come to realise is that, the biggest puzzle that is missing now is the "Order Book" itself. If this Order Book is found and known, it can help to answer the OP's original questions about :
Who places them?
Why they place them?
Where they place them?
Correct if I'm wrong, but I also realise from what I gather in a very short span of time that Order-Flow Trading is not the same as normal Chart Trading.
Just chipping in my thoughts and hope I am not confusing anyone.