Catherine the panel blinds could be your solution. They are available in sheers, patterned, mixed etc and operate on a track system. It's an update of the verticals that a lot of homes have. If you have Ikea in NZ you could sus them out there.

Any rod will work that does not have decorative finials. A U shaped rod. I would prefer sheers and drapery that go to the floor. But you can use what you have also. A roman shade can take the place of the sheers and mounted inside the frame. You can use ring clips for the drapes for easy opening and closing. Thank you for the new photos.

Top down bottom up blinds? They come with an aluminum coating too (to block sunlight and thus heat). In our bedroom we installed 2 roller blinds on top of eachother. Both white. One translucent for privacy and one to darken the room. It was cheaper that the dual layered (cellular) blinds and I did not want foil. Not sure if you'd have the space for that (we insulated the walls from the inside, so our window frames are quite deep).

Your deck will be amazing. It has fantastic form and plenty of architectural interest, it will add enormous benefit to the front facade and street appeal. I love your palette, it is simple and still has point sof interest. MY suggestion would be to use a combination of your exterior colours applied where best to highlight the deck structure and either tie in, or accent against it. Ding all of these things by painting the lower retaining section in the base grey the charcoal colour to continue and blend into the lower floor brickwork, also do this charcoal on the upper deck frame which is also the roof of that entry way. I am trying to say that thick timber which trims the deck. And the slatted section of the stair wall which acts as a breezeway in the light grey- why? Because the open sections of the slats will always appear black as you can see through them to under the satirs, and the light grey slats will stand out and feature that shadow line, perhaps even use liting to further enhance this detail. Lastly, the stair treads themselves left natural, like an architectural contemporRy stAtement, the natural timber tones will be rich and sophisticated and act as art inviting you to the home. These stairs would really pop and be commentedon at street level, also consider lights in each tread, perhaps the slatted wall side to highlight both this and the stirs for night practicality. What a stunning entrance. The natural character in rich timber tones will warm the grey, keep it contemporary and not introduce personalized colour, which can take away from street appeal. This on the other hand, appeals to everyone. And greenery, landscaping will only take this to the next level. Literally!