Textured linen or with a subtle print wont date. Feature walls make a room smaller as they jump out ar you. Wouldnt recommend. Get some interesting art or craft. Pick up colour with accesories

Is this picture taken during the day or at night? If it’s daytime your kitchen must not get much natural light. Go for white cabinets to reflect as much light as possible to brighten the room up. Boring but timeless & always looks fresh. For colour you could do a splash back, or just add colour via accessories such as a bright kettle/toaster set, tea towels etc., easier & cheaper to change if you get tired of it.

Personally , I wouldn't use that wallpaper -- it doesn't suit the apartment style IMO . I assume she wanted to add some focus and colour , but to me it doesn't work . To make it work ( or at least not 'jar' ) if she does insist on the wallpaper , pick out the burgundy or red of the wattle flower ( or whatever it is ) , and do a wall opposite it in that exact same shade , or maybe the kitchen area if you have good masking skills . The animal skin rugs look great , but the couch is 'lost' -- add cushions in the same red or burgundy as the wall , or go even brighter red or burgundy . Rest of the walls can be left as they are ( depending on wall condition ) or any similar neutral ( aka bland ) grey or cream , or possibly even a light steel blue .

For a pass through window to be very useful, it needs a surface to place items that are being passed through, that can be easily reached from both sides, or you would need to coordinate people inside and out to pass things, which isn't feasible. I would consider whether it will be used as a pass through, given the door is immediately beside it. A small breakfast bar that uses the window for a view can also be useful for a pass-through set-down surface. Make sure the window is large enough to give a line of sight from person to person so that it is easy to communicate between the spaces - along the lines of 'Could you grab another beer?' or, 'I forgot the sauce.' I would also make the pass-through window a little wider if you do have a seating area, so it looks big enough to be welcoming, or it will be less likely to be used. At 2.500 deep, the deck is not large enough for a comfortable outdoor dining area of more than a couple of people. You need 600mm for comfortable seating on each side of a table, plus the table width which will be 900-1200, and with this layout, you also need another 900 mm to allow access past this, to the pass through, the seating and to the steps down, and with the deck being above ground level, space for access beyond the seating on both sides of the table is a good idea. If there is a barrier, you can get away without it because chairs won't fall off the edge, but it does make things tight. That adds up to at least 3000-3500 and preferably more. You can make things work with a tighter space, with a compromise to fixed seating along the edge, and a narrow table.