One possibility would be to swap the living room and the dining room. Since the current living room is larger than the current dining room you could still keep some comfortable seating (couch and upholstered chairs?) against the front wall for a keeping room/dining concept. Then your new dining areas (kitchen and dining room) and living areas (living and drawing room) would have good flow between them, which would work well both for family and entertaining. You could also add some builtin bookshelves in the drawing room or new living room to create a library area to add another fun element to the living areas. These bookshelves could be against the long walls in the drawing room, around the window with a window seat in the living room (former dining room), or built to create some separation in the open area between the drawing room and living room/stair area. Your plan seems to show some sort of builtin there, but I'm not sure what it is.

You could also bring in some texture with bamboo sticks or decorative branches and help balance a bit the height of your room with small scale furniture. Spray paint them if you find the perfect size and shape but they aren't the color that you need. Ikea carries white decorative stalks for a very good price. the ones in the 1st picture hold well with small kids around and you don't need a vase for them. there are washi paper or crinkly paper floor lamps with a soft beautifully diffused glow For a budget friendly version check ikea or target http://www.ikea.com/us/en/catalog/products/80028552/

There is contrast between the traditional furniture and the focal point of the floor which pops, draws attention. I would recover the sofas in cream colored soft fabric - suede. I would leave the curtains grey, and put down a large neutral area rug. The edges of the room would show the pattern of the floor. I would color the wall and add texture to it, but not too dark as the room will appear smaller. Add a picture and put a nice plant holder, large vase in the left corner of the room - an oriental-style vase. Or, a cream-stripe fabric on the sofas. You could go soft or bold in this room - depending on your taste.

Is the indent in the wall where you have the TV now, supposed to be for a TV or is it to be a closed up closet?? You could switch the room with living area where you walk in but then you cannot wall mount the TV due to windows. Plus you might like eating near windows for more lighting drama. Also , now seeing your hall , I think turning the dining table 90 degrees from how I placed it, would fit better in your space. You could consider an area rug under the table as well , which would help to define the space when you enter. Also keeping a runner and a vase with either fresh ( or nice fake) flowers on the table, will make it flow better with the living room area furniture.