Have you thought of rearranging the furniture so the tv isn't the focal point? Furniture against walls can make a room appear smaller. If the budget permits I would add a coffee table to bring furniture into the middle of the room. I would also add a mirror to the dining area to bounce light and maybe install a low hanging pendant light over the table. I would also choose a neutral coloured rug as using a single colour for an item becomes the focal point. Grey is a good modern neutral for walls. If you want to use paper on a smaller wall choose a small pattern that won't date unless you don't mind repapering to keep it up to date. There are some really fantastic papers around at the moment such as chinoiserie, bold contemporary and typography but it depends on your preferred style? Maybe use plain (not patterned as this may date or your taste will change) velvet or silk curtains to soften the room. Use different colours and textures for the accessories to avoid block colours as per comment above. Pattern/interest can also be added in the form of wall art.

Hello, This seems to be a huge renovation! For the floor plans, you may want to use https://planner.roomsketcher.com. It is a free tool, and probably one of the easiest to use, moreover if you'd like to use our construction team's service you can make a floor plan by just handwriting, so we can send you a quote, but honestly, it would be better for you if we could come for a survey and make all the measurement by ourselves. Let me know if you are interested so I can arrange our managing director to call you. :)

Going back to a decent layout and taking account of where the electrics are and the radiator, i'd ditch the large dining table idea. Go for a small drop leaf table that can be brought out and extended when necessary but is small enough to provide eating for two the rest of the time without being in the way. You can accommodate two further dining chairs elsewhere to bring out when needed. At least that way you get a good lounge layout. Plus you now have room to walk around and get through the patio doors.

Short answer... Yes Long answer... it depends