All fixed - I assumed it was a reserve blockage from the above thread, so first drained the reservoir as much as I could. Below video link shows how to, but instead of using a pump as per the video, I just went down to the variety store and in the kitchen section picked up a $2 cooking syringe (flavour injector, which holds a couple of fluid ounzes). Then attached some plastic aquarium pipe (about 1/4 inch dia and about 6 inches long). This was perfect to get thru the reservoir hole which is only about 1/3 inch.
I then removed the inlet and outlet pipes. The reservoir then pulls off the metal bracket, as it has two plastic lugs on its underside that mate with rubber mounts in the metal bracket.
The nylon mesh microfilter at bottom of the reservoir did not look too bogged-up, there were some fragments but is a VERY fine mesh, so figured would not take too much residue to impede the flow of the fluid.
I gave the filter a good blast with degreaser, then slooshed the filter a few times with more degreaser then flushed for a few minutes with cold water and air dried in the beautiful Sydney sunshine for 20 minutes. Double checked it was 100% dry then reassembled.
I refilled the reservoir with clean fluid and when I restarted the engine, the change was almost immediate. The pump screeching noise completely disappeared after a few seconds as the fluid (assume now circulating properly) made its way thru the system. The steering wheel felt immediately lighter to turn. I then did approx 6 empty-then-refill flushes per the video, starting the engine and turning the wheel inbetween and the fluid changed from a brown colour to dark red. The system is 0.9 litres, I flushed the system with about 1.8 litres of new fluid. The fluid was noticeably clearer and about half the viscosity of what I had flushed out too. (probably still need to put another litre thru it to bring the fluid back to a lighter shade of red).
So with the job completed, the power steering is now much lighter as a result, the reservoir no longer leaks thru the lid and the pump noise is all gone - so appears fully fixed for $22 total cost !! :-)
One tip if you think you have a similar reservoir problem to this, is to check your reservoir with the engine running. Look at the side of the bottle, the top fluid line should be clearly disrupted and agitated due to the fluid circulating thur the bottle. If there is not much movement of the fluid surface - you have a circulation issue with the reservoir or pump or other blockage, but as I have read in this forum and from my own experience here - ALWAYS start by reservoir cleaning and fluid flushing as described here firstly, as could save you big bucks.