Do you have any photos you can share? We do better with both floor plan and pix. I think the 9' area should be devoted to a library/reading nook with bookcases on the two walls and a comfy chair and floor lamp for reading. I see lots of doors but no windows in your space. The stretch of space from the entry to the balcony/gallery should be kept open for traffic flow, so Place the FP on the 7.5' wall to be seen upon entering. I think 'd try a sectional with two equal wings. Put the TV on the 7' wall between the two doors and float the sofa so one wing faces the FP and the other the TV. Use a credenza 25% wider than the TV rather than a TV stand. In the jog that has a 6' and a 4' wall, try a family game or chess table and stools. Be sure to get a big coffee table made of reclaimed wood so people can put their feet up on it.

For the dining room, I think I'd orient the table 90 degrees from how it's drawn, and I would make it a drop leaf or gateleg table so that it can be made smaller when not being used for dining. I would embrace the idea that the entry is right in the middle of the living room, and bring the living room furniture out towards the fireplace so the fireplace is connected to the seating area. Maybe TV above fireplace. In that back corner where the sofa is drawn, I'd make that a small work/office space.

I am an amateur lover of home decorating. I too have a very awkward long narrow living room that is 350cm by 620cm. Additionally it has diagonal traffic flow from the front entry to the rest of the flat. The owners have built a cabinet at one end for the TV, etc. I think I would make a cosy seating area at one end of your long living room. Place a grey or brown sofa at one end but not against the wall. I like the idea of a narrow console table behind the sofa with a table lamp, a plant or a large statue. This brings the end wall closer in. A peachy or raspberry carpet in front of the sofa will pick up the wall colour and anchor this seating area. (grey and some browns also coordinate with raspberry/peach). A couple of raspberry sofa cushions can help include the wall colour into your overall scheme. Single chairs opposite the sofa allows visual and actual flow down the narrow room and completes this seating area. At the other end of the long narrow living room I would place a reading chair, a floor lamp and a small round coffee table. If there is room you could have a tall bookshelf with you favourite books. What do you have on the long side walls? I have windows and doorways on both long sides. I decided to use pull up shades on the windows instead of curtains which I thought would make my narrow living room look more narrow. The wall colour is white but I think I will tone it down to a soft grey. I plan to paint the end walls a darker grey.

Its just really messy right now. Too many colours and clashing prints. Is that Puja unit lime green? Or does it just appear that way because of lighting? Either way, it stands out like one more distraction. Pick one base colour add and add prints that go with that base. That TV unit HAS to go. So do that black metal coffee table and the carpet. I would suggest you go with a simple geometric print in the carpet. But apart from these obvious design gaffes, the structure has distinct possibilities, if you do a classic English style. The railing above adds some interest