1) Kudos to kvinge for pointing out that a text display before the level exists (how could I have forgot about the decription? Probably because Chronic doesn't use it yet.). This is an easy update for the next Pfx version: add "tutorial" descriptions to some levels.
2) I suggested 1,2,3 for demonstrating the following:
1: you making a non-horizontal deck, simple reinforcing
2: using the riverbottom anchor to build a tower, and from that hanging a cable-stayed bridge
3: cable-stayed with off-plane mid-air anchors
What is missing is an arch design, with the "riverbank" anchors for the arch.
I would not change any of the existing levels (except the descriptions, of course) because that would make comparing scores a pain in the butt. A tutorial map pack might be the way to go.