Shame you can't change water suppliers like you can with everyhthing else
The first line said something like "receives any of the following..." I dont think you need to qualify for all of them alltogether. [But missed the "And in addition" oh dear. But hopeful, I reckon call and doublecheck]
Meter saving yes, when I was in a 1 bed flat and paying more than my mate on a 3 bed house just 2 min wak away. Got meter and went from £30.00 a month to about £10.00 but that was in the 1997 i think. Waster sure is for meters and water sure plus is for non metered.
Free water in Scotland is understandable considering the abundance of it. Really they should be charged when they get Sun.
We qualify for our water supply (Affinity) but not for our drainage (Thames) as they take into account your benefits when assessing household income :(