Leather sofas can really dominate the room and can give an overall cold feeling. I would add some earthy elements, like a wood coffee table with glass or metal. Go to Restoration Hardware's website and look at their sofa room scenes. And I'm sorry I think the art is too harsh for the room. That's all your eye goes to in the room. too overpowering. I would look for something softer or maybe a cool mirror and I would add color to the room with pillows and some colorful lamps. I also think woven blinds would look great. They add warmth and give a finished look. The color of your window treatments should contrast your wall color a bit, not match it or else it starts to look generic and blah.. You have warm walls, warm floors and the woven blinds, like Hunter Douglas brand would pull it all together for you.

This is the kitchen plan

I thought of two options for the headboard one is keeping the way it is now i.e gold color or change it to dark brown velvet, because my bed is wooden (dark brown), so I thought the headboard will just look like a part of the bed, and I could do the drapes of sea green color. The sofa chair next to my bed is not there anymore, so on this wall its only the bed and the window. Bedding I have to change, but thats not an issue as of now. My main concern is the drapes and the headboard which have to go with the wallpaper well.

I have some suggestions if you are thinking budget friendly changes. Make a photo gallery with different size frames and arrange them parallel to the stairs, so you can enjoy each photo as you climb up. And for the area that will be on a level with your upper floor, try some pretty decal that will connect the photo gallery to upper level. And last, if you have budget add some beautiful hanging lights in the stairwell. Also think about repositioning your refrigerator.