Agree with the majority... use hearty plants , that love the dry hot conditions... don't worry you have plenty of choices and colours so there will be colour ! A good organic soil that has been turned well! Plenty of good water between days that at hot... But most of all , your mulch is the key factor here if you don't use a good one , all will end and quickly ... some mulch tend to disappear quickly , some seperate in large water drenching . Because you are on the slope maybe try running Hardwood timber palings from end to end in around 3 sections to stop the mulching sliding . And my choice of mulch Hardwood Chip , not mulch but chip lasts for a bloody long time ! I'm a cabinet maker via trade but love green thumbing

extra fascia depth would be dependent on how much you want to spend on extra labour by not using standard steel fascia (which is only about 185mm wide) with all the standard fixings ..A carpenter or plumber should be able to make a wide substitute out of sheets of ribbed colorbond steel and the rest should be standard timber framing and soffit linings but check wit a carpenter or roofer about what you want to achieve (why does it need to be 40cm wide??) and there may be a very simple alternative available

You have posted on the Australian houzz site. But we can still help. Which would be used more, the desk or the guest bed. If the desk than I would have a sofa bed, which can be pulled out when needed, but a sofa when not needed. Gives you more room for a home office. The photo you have posted of the bed, that is a sofa bed. If the room would be used as a guest room more often, then make the wardrobe space into your study area. When guests are there, you can just close the doors.

You could try Wet & Forget on the driveway. You can buy it ready to use and attach it to a hose or buy a bottle that you dilute to use in a sprayer. I have used it and it works - slower than water blasting but it won’t damage driveway if it has some damage? I can’t quite tell from photo if that’s grass clippings/mulch or broken concrete on driveway? If you use it be careful not to spray garden bed. I live in FNQ and we planted seaside daisy - doesn’t need watering but it also won’t die from our wet season. It’s a ground over and spreads out beautifully in a courtyard area that’s get a lot of sun. Just needs a trim from time to time. I see you have Rio (purple green ground cover) which you could separate and plant down the path but it does like water. Maybe for the fence you could try attaching lattice to it and plant another passion fruit vine to help cover the whole fence. It does look like you need to get rid of some woody parts of the passion fruit. It’s a tough plant and will enjoy a bit of pruning. We had one that I thought had died last year and it has returned with no help from me. Be careful with the heliconias and gingers ... they can get out of control if you don’t stay on top of them. Anything tall will cover your fence but it will also cover the passionfruit vine which obviously loves the spot it’s in. Good luck!