sensible,
I don't think you've lost the plot, just the storyline....
Ive never suggested that this idea would work at all airfields, and was never really aimed at the bigger airports. At smaller airfields where the NIMBYs' are at their most destructive, it is a way of increasing circuit height, and at the same time shrinking it. I'm personally fairly sure that in a wide descending turn from 1500' to final there is ample time see the runway.
At the moment there is hardly a standard circuit pattern anymore, especially at the more threatened airfields, so ppr is more than ever needed to get the latest circuit info from the operator. That being the case, all aircraft arriving at an airfield should know the procedure and follow it, even non radio aircraft.
As to you're second scenario: I think that would be a potential problem whatever system was employed.
Point three: no you're not being thick, but contributing to a topic related to an important issue, and one to which I and many others think a bit worrying. All ideas need some consideration, and I'm not so brash as to suggest that my idea is the panacea that the GA world needs.....Any other ideas anyone????