An L shaped design sounds fine to me and I think it's practicality will outweigh concerns about it dominating. I agree a soft white is nicer in an older property and a more modern look than gloss but I don't agree that a painted finish is better with young ones as it can chip- I would look for a laminate door which despite being perceived to be lower quality will likely stand up to rough treatment

Hi Sophia, I think the floor is the most important thing as it won't be changed once it's down, paint it relatively cheap. The best advice I could give (based on my recent experience) is that if you put a cool grey floor in a room that's filled with sun it's fine. If you do the same in a North facing room it can feel gloomy and cold and then you have the option of taking well known advice for a North facing room which is 'opt for warm, creamier colours for the walls'. Well this doesn't work too well with grey floors, it can look sickly. Therefore, the floor is a consideration at this point. There is a gorgeous tile from Topps called 'Sculpt' in beige which is the very same colour as warm concrete and it has an amazing look to it. General advice is to avoid cold greys in North faicng rooms and opt for yellow based neutrals. I have used Skimming Stone in my kitchen (North facing) but it's got lots of natural wood. Off white and Shaded White are both recommended for North facing rooms. https://www.madaboutthehouse.com/choosing-the-right-shade-of-grey-paint/

If it were me firstly I would have one switch for task lighting- I think your planned 4 spots in the island boxing is enough but would have them in a row. I would have an additional 4 in a row in the ceiling above the walkway between the island and the main run of kitchen cabinets plus an additional two behind the sofa (but put a softer bulb in these). I would have two in the ceiling above the sink as I think it is tidier than having a wall light. Don’t forget to put a few in the laundry cupboard too. Since your extension ceiling is sloped I would have inset spots that you can angle. Personally I think that when you use the desk you switch on a desk light. I would have a ring of 3amp sockets so that you can switch on two table lights in the sitting area and two standard lamps in the dining area (or two table lights on a console table) and the LEDs above the bookcases. In my opinion you specify more than you need as you don’t have to plug something into every socket but the flexibility is useful. Personally I don’t think you need the coving light in the sitting area and think the idea is odd in an area with sloping ceilings. Next I would have additional kitchen lighting - I would have a run of LEDs under the base cabinets near the plinth and around the base of the island- these are nice to have on at night when watching TV as the kitchen is not fully lit but is light enough to navigate. Additionally I would have lights above and below the wall cabinets. I also like your idea of the boxing above the island having a shadow gap to conceal further LED strip lighting. Pendant lights- I agree that you won’t want one in the sitting area. I think it is messy to have pendants over the island with the additional boxing. I would have one over the dining table and choose an oversized fixture later- ensure that this lighting flex is near somewhere strong enough to mount a ceiling light of some size. Additionally I would have walk over lights in the floor near the garden doors. Remember these will reduce the focus of the garden at night- you might prefer to put these on the outside of the door to reverse the effect. Don’t forget to specify at least one socket behind the cabinets/ under island should any of the kitchen cabinets include lighting- this is especially useful in pantry cabinets. Don’t forget that you will likely need additional sockets in the laundry cupboard as you might well have a charger in there for a vacuum or drill. Personally I would have extra sockets around the desk and contain the router, you home answer phone, etc etc all in the same place. Don’t forget you can also get sockets that include a USB charger inlet. Since you are doing a plan for electrics don’t forget tv/ satellite aerial points. You should also take this opportunity to consider outside lights and power- consider sockets outside for garden lights, outdoor heaters, awnings, water features, mowing the lawn etc. LEDs unless you like decorating in very dark colours choose warm white lighting- a lot of strip LEDs can be adjusted to color match other lights in the room. LEDs- Last time I sourced these I was disappointed with the quoted costs from the electrician- do your own research online about price. Pay attention to the lumen levels and consider if you want disable LEDs. Boxing over the island. Choose your extractor before specifying the size of the boxing- I think the shallower extractors are deeper than the 20cm you stated.