>>low water pressure (which results in ‘soft water’ instead of... hard water)

Sorry to be 'that guy', but water pressure is unrelated to a water's hardness - which has to do with mineral content (typically calcium or magnesium) in the water. From your mention of shampoo, I would guess that the water is rather hard. It varies from aquifer to aquifer here in the US, and I'd imagine it's the same in Scotland.

Otherwise a great post. :-)