Lovely print. I had a peacock feather print and I had a colour called glacier Grey behind. Think it was Wattyl . Again like your other walls it is a greenish grey but darker. I also had my prints on a charcoal wall..loved that too. As you said the picture ties in with the chairs and now it's not necessary to add more matching colours. I'd buy a couple of sample pots and paint large pieces of cardboard. With the other walls I would consider painting them in whisper white (Dulux) a very universal colour that ties in nicely with all colours.

I think  wallpaper mural style or otherwise is a really bad idea on this wall.  It's already a very busy space and tv on a busy background will make it worse.  The fact you don't know where to finish it tells you this is a wall where it won't suit.  Save your money.

I probably wouldn't use another wood - but as others have said it depends on surrounding area and where the shelves are actually for. Personally I reckon I'd go plain black or white.

I would recommend that because you are so unsure you either call in a Dulux colour consultant, they refund if you buy their paint. And or purchase a small pot of each colour, apply to a piece of render board approx 1m x 1m and stand up against the walls in different places and light/time of day to see how it changes. (or are you able to paint some of the wall that's plastered) My preference for the Winter Fog was that the Winter Terrace is too blue, For me Winter Fog relates better to the Grout in the stone Dreamers example shows a WHITE house, cheers