Certainly agree about loosing the curtains. Either silver venetian blinds, vertical blinds, or plantation shutters would make that area cleaner and tidier. (If you are not overlooked, how about leaving any window coverings at all). As for the feature wall -not sure about the white brick effect, as I feel that there would be too much of the same colour, and it would not stand out as a feature wall. There are many softer shades on the market now, and depending on the remainder of your room, choose a soft shade, either duck egg blue, or soft plum, and use this colour to accessorise in cushions, or a picture in same colour, but something else to bring the items together. With the emulsion, I would use a soft sheen rather than matt, as the soft sheen is easier to clean (I notice you have children), and reflects the light back into the room. Hope some of this helps.

Your new furniture looks lovely. A vibrant blue would work well with the white and wood furniture and also your sofa. You could think about a feature wall, (behind your sofa maybe) and some new curtains that pick out the chosen colour. Keep the rest of the scheme neutral, some black and white prints on the wall would add a hint of cool and also bring in the grey sofa cushions. Good luck!

If you close the door and stand in the dining room you would paint the frame and door the same colour as the rest of the woodwork in the dining room (colour A). Then in the hallway you paint the door and frame the colour chosen for woodwork in the hallway (colour B). On the side of the door where the latch is this would be painted colour A if the door opens into the dining room. Hope that makes sense!

The human brain prefers symmetry so the room is looking odd right now due to the fire/tv, - it could be that the fire is actually centre in that wall, although it appears not to be. I would add a custom built-in in the space to the left of the TV. Make it floor to ceiling and to fit flush with the fireplace wall to give the illusion of one long wall. You could get a joiner to build it for you or as you like to create for yourself, do a search of Ikea Billy bookcase hacks. I have seen a lot of people use these to be very creative when making built-ins. Assuming the fire and TV stays the same, to balance the wall the other side, add some very slim shelving at the same horizontal heights of your built-in. A value for money solution here would be Ikea picture shelves. They are very slimline (they won't stick out far from the wall) and you can stand photos/art of them or small ornaments. I would think about a couple of lamp tables to add some lamps and accessories. Not sure if you are changing the colour but I would also add an accent colour (or two) and maybe use it in a rug and some cushions or accessories and art. A coffee table may also work - maybe glass to give the appearance of that space still being open. On the back wall behind the sofas how about two large pieces of artwork either side of that middle section. I would also get rid of those wall lights as they are not wired in.