I just found out that blue green colors really bring out the beauty of wood. I know its not the same but I have honey oak cabinets and just repainted my kitchen a blue green and it really made the cabinets look stunning. Maybe you could try something in that color family to enhance the wood. Just a thought.

Deep gray and all the other accents in silvery old wood and cream. This will add drama, allow the other elements to bring ion light and set off the concrete wall as a true feature. If you want light instead of drama, then go for a very pale beige stone. It will echo stone colours in both the concrete and rocks...

I have western red cedar shutters and I went dulux antique white. Painted on the wall and ceiling.

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 .