Please post photos, and dimensions.

Looks like the drain that the down pipe goes into isn't working as it should, over flows before water enters the drain. Love the random pavers, these could certainly be reused adding a few more to replace the bricked area all on one level as this would enable a better space for outdoor table and chairs. The pergola is tired and would be great if as you mentioned could be raised up a bit, depends on what the Body Corporate will allow, a couple of see through panels inserted above next to the building would help with light. A BBQ kitchen on the back wall, plus I would try to re swing the door back to it, the door gets in the way as it is, can it open inwards opposite the sink. Certainly keep the garden beds it will help soften all the hard surfaces, taller planting along the boundary will also add privacy cheers

Can you paint the fence dark because that would make a world of difference to the area? I'd go monument. Dark fencing makes them recede. Then follow earlier comment with lilli pilli. winter lights works well or something similar.

For low maintenance in such a variable climate while preserving light access I think I'd go for some kind of a translucent decorative screen, with maybe just a few potted plants to provide some greenery. If they're not planted in the ground you'll have to be even more careful to ensure they get enough water. Or, thinking further, I've seen Chinese star jasmine used in challenging commercial locations, including as a screen around a cafe's outdoor area, it looks amazing and appears to be very hardy and copes with a temperature range similar to yours. Two drawbacks though, some people dislike the smell and it needs pruning so not low maintenance. It's difficult finding something that ticks all the boxes.