Inds, one thing that you need to think about is how you deal with the "external" corners. Forgetting this is a common mistake and means that the edge of the tile on one side or the other is exposed and this often leads to an ugly detail. With natural marble the option is often to mitre these edges and then lightly grind off the sharp edge to protect the stone. This is not n option with ceramic or porcelain tiles. I would try and find a tile that offers porcelain or ceramic trims which give a nice neat edge detail such as https://www.architecturalceramics.com/bianco-carrara-5225 If these trims are outside of your budget then there are a variety of stainless steel, aluminium or plastic options available, but ask the question of your tile supplier. Best of luck with your project.

The best advice I could give is to build the units that are against the wall out by about 15cm and then create a raised shelf. Not only would this provide a good place to store oils etc, but that amount of gap is enough to possibly keep a lot of splashes away from the wall. We did this in our kitchen and tiled the wall with riven slate tiles. Three years on we haven't got around to putting up an extractor fan, but the wall looks the same and is unchanged. We sealed them with a stone sealer and put lights above to highlight the texture.

https://youtu.be/5fgFQhMm5Kc See how he applies two coats and with the last coat still wet rolls everything again in ONE direction. Best of luck! If that doesn't work out try a last layer with random all direction brush strokes. It will give some texture, but at least no boring stripes. ;)

Hi I would put a large rug under the table to add some softness and colour if that’s your thing. I think you should consider either a long dresser or a sideboard for the wall between the square window and the tv room. This could then I troduce some interest to the room. If a sideboard you could have art or a mirror above and lamps on either end to add some warm mood lighting. If you went with a dresser you can display all manner of things on it - decorative plates, cups, vases, trinkets and also have lamps on it however a dresser is probably a bit too traditional for your room which has a more modern feel. Maybe a comfy chair and tiny side table in the nook under the square window to sit and enjoy the view. It will be lovely once you have added final touches!