First question, does it work or are you presuming it does?
What was removed from the brickwork face?

Patching is patching. Surface will reveal what you've patched and where you've patched.
Rendering is the only way to guarantee a uniform surface.
Do a little, get a little.

Tank size is only half the equation. Roof size for collection is the other half.
Tank type, sealed, concrete preferred, galvanized as alternative, not plastic
The harvesting system is connected as an…

Use 50mm rockwool fibre insulation if it concerns you that much.

To begin with what happens in Qld. is different as to what happens in Vic.
Qld has higher humidity to begin with whereas Vic is drier
When assessing humidity from area to…

"Could I get away with just putting in an electric wall heater like a NOBO and avoid an air con?"
more than likely

Get an architect

...and to think the Arabs live in comfortably in tents

and what is the cost of energy consumed?

How about you just ventilate to atmosphere with a Condor purge vent

I doubt it given that it's air movement that carries away moisture from the laundry

I knew a fellow that built a house with characteristics similar to a plastic bag.
He was happy with the reduction in heat loss but then complained about there not being…