I would be inclined to go with an unobtrusive light since it's the living room and anything too dramatic or a hanging pendant may interfere with your peripheral vision (or otherwise be an annoyance) when you're watching TV, etc. Also, being so near the sliding door, the wind may cause a hanging pendant to swing quite a bit which will cause the lighting to be constantly shifting and changing which I would personally find annoying. I'd go with something simple and subtle, but look at getting a tall standing lamp for the corner near the sofa (or possibly at the other end of the floating TV cabinet). In terms of warming up the apartment, I think you need something on the bare walls. A smaller picture above the floating TV cabinet will help to take the focus off your TV. A larger art work behind the sofa will also help to add some colour and personality, especially if it picks up some hues from your sofa. If you don't like the little Buddha statue, I would look at adding one or two other items that you do like (perhaps picking up colours from the wall art) and making a little vignette. A couple of colourful cushions and a storage solution for the wires, games console, etc on the floor would also help to bring everything together. Something as simple as a woven basket under the floating TV cabinet might help to keep the games console, etc in place unless it is in use.

Other colours that work with red are turquoise, apricot, peach, any blues, yellow, even some pinks and greens. (Look to gardens for inspiration, or Old Masters paintings). I'd find patterns with combinations of those, or Vys colours, in a rug, and chairs or cushions.

To be blunt -- the room isn't really big enough ! So you have to sort out priorities , and space . You have a dining table , and a computer desk . Can you get rid of the computer desk , by having your computer tower mounted behind the couch or similar , and a wireless keyboard and mouse that you can use on the dining table ? Mount the monitor on a wall , or if you don't need in depth graphics , I understand you can use your TV ( I've heard something about the 'refresh rate' is less on a TV ? ) . Maybe even have a monitor but also the option of using your TV ? Could you use a 'breakfast bar' , probably where the computer desk is now , I know its not sociable all staring at a wall , but it would/could serve as a brakfast bar and computer workstation . Could you get rid of the dining table and chairs , and have a large coffee table , or 2 smaller ones , and eat 'casually' ( my polite way of saying eat sitting on the couch ) ? Even mounting the TV on the wall will let you get rid of the cabinet , but I gather you have gaming consoles in there ? And the present arrangement with the pot plants uses some space -- maybe some shelves with them on will still retain the plants but free up floor space ? Just some thoughts off the top of my head .

What is in the second photo, a power point? And you think the tv socket is going to be in that same wall? Then that is where the entertainment unit goes. Is that the only power point? When you buy your entertainment unit choose something which allows access for plugging in the vacuum cleaner. Unless you have a rechargeable vac which doesn't need a power point. With hard flooring perhaps you will mop more than vac. Although if you want to soften or warm the space you might have a rug? I didn't understand "combination of bright and neutral colours" until I looked at your Idea Book. You have some lovely pictures there. Do you have any artworks yet? That might influence which colours you repeat throughout your space. The grey sofas are probably the most versatile and timeless, and something like that might be the easiest to source in a size and configuration to suit your needs.