Can you give us a diagram of the floor plan, showing door and window placement? We can't tell you where to place the window except to say on an outside wall, right?

Adding taupe or beige to the walls, in most hues, would blend in too much with the draperies. I love the lavender in the bedding. It would pull the room together if you were to choose a grey paint that had elements of lavender or berry and silver. The color would be subtle, neutral, relaxing as well as refined. This slight shimmer will pull out the subtle nuances in the marble. As the headboard is already so interesting, it would be too busy to add anything too ornate on the wall. To open up the room and increase the light, you could hang a mirror. I would select an Art Deco style with metallic accents to continue pulling together the room. The marble is lovely, but combined with the sleek lines in the bed and bedding it creates a very smooth appearance. To create warmth, it is necessary to add additional texture. I would add a soft, plush or high pile area rug by the bed. How nice would it be to step out of bed on to that?

You could head to Ikea if you're lucky enough to have one near you. Their Billy bookcases with the added height pieces are wonderful and are available in a black/brown color.

Yes, moving the bed under the picture wall would be good, and provide space for a chair and ottoman as you mentioned. And i have actually put a new set to curtains today which is a slight brown colored one. And I was thinking about painting the walls with the picture and the one with cupboards in a dark red shade and the adjacent walls something between off white to cream color. I plan to change the floor tiling too, but not at the moment. I've been thinking of making it a wooden flooring. But not sure what color to use.