None of these questions were asked by the Telecom operator. The fact that it is an overhead line was enough for her to cancel my order. It is in fact a single span line which cuts across the corner of my neighbours property, but they don't know that.
I was going to do a chat with Telecom to confirm that my overhead line was ok. But no, I'll wait for the Chorus guys to make the decision on the ground where they can see the actual setup.