If your house is at stage 14 and the first fix is just being started, its hard fro me to see how so many stages there were!
Foundations, Brickwork to DPC, Drainage, Ground floor, brickwork to 1st floor, joists, brickwork to plate, roof trusses, roof tiling. I suppose if they included each brick lift and scaffolding as a stage maybe!
I am pleased you are safeguarding yourself.
You could inform the Local Authority of the planning breach.
However, Story Homes should sort this out prior to legal completion, especially as the scaffolding is still up presumably.
As for damaging the roof, if the tiling needs to be replaced or there is any damage whatsoever, that will also be a matter for Story to address not you to worry about.