If you love that wallpaper, use it in bathroom. Not really right for behind bed. I would go a drum style chandelier. In a silk pale gold. Your bed looks zen or Asian to me. I love it. But, you don't. Need to much with it. Keep it simple a more formal drape on windows, color would depend on wall color and bedding. I'm thinking a dramatic peacock satin. Use a lighter same tone on walls a rich teal. Ceiling can be gold leaf. With alight that cast shadows on ceiling at night. Then your wall paper will tie in. Furn should be mirrored.

If I am having trouble finding a rectangle glass top table I usually order the glass from a local (to the location of my Client) glass shop and then the base from one of my furniture vendors. a dark table with your light chairs should not feel dark given that it is in a room with what looks to be lots of light with the large glass door and side window. I do think the glass would be perfect for the area. What size table are you thinking will fit the best in the space and for your needs?

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.

I feel partitions are not needed. You already have too much for the space. Adding a partition will shrink the space further. The simplistic solution, you do not wish to discard any furniture would be to paint all the walls in lighter pastles. And use some wall painting frames to highlight certain walls.