That's not really the point John. The water regs aren't really bothered about the salt content of bread!
But they do set a maximum sodium level, above which 'softened wholesome' water ceases to be wholesome.
Not true, indeed, while sodium levels are below the limits for wholesome water, softened water should be tested for sodium content before it's supplied for drinking.
It may just be easier to take off drinking water before the softener; as the regs guide advises...
He doesn't only want to pump the hot. He wants to pump hot and cold to one shower!
Placing the pump on some sort of insulating material (like carpet) will reduce noise transfer through the ceiling. You won't silence it completely and don't think about building a box around the pump to quieten...
That's quoting a flow at a certain pressure. Flow rate isn't measured in bar.
I think you may have found a typo which coincidently and unfortunately appears to match your requirements - it should say flow rate at 0.5 bar =13.3 l/min.
Could you pump it?