This is a helpful podcast if you are thinking about what size of kitchen island you want or what to go for: https://shows.acast.com/love-your-kitchen/episodes/exploring-function-over-aesthetics-with-amnda-hughes

With pine green cabinets and white worktops, there are several colours for the kitchen floor and wall that would complement the colour scheme nicely. Here are some ideas: Neutral colours: Since pine green and white are both strong colors, you may want to consider using neutral shades for your walls and flooring. Colors like beige, cream, or light grey can work well to balance out the stronger colors in the room. Lighter shades of green: Another option is to use lighter shades of green for your walls or flooring to create a cohesive look. A pale sage or mint green could be a good choice, as they complement pine green nicely without overpowering it. Warm colours: If you want to add some warmth to the room, consider using warm colors like terra cotta, mustard yellow, or burnt orange. These colors can add some depth to the room and complement the pine green nicely. Cool colours: On the other hand,cool colours like navy blue, teal, or slate gray can create a calming atmosphere and complement the pine green as well. Ultimately, the choice of color will depend on your personal style and preference. It may be helpful to gather some samples and experiment with different combinations to find the perfect look for your pine green and white kitchen

We just repainted some doors in a rustoleum kitchen cupboard paint which is a darker colour but it was painted on with a short hair roller and you can't tell its been painted by hand ie so they might not use a brush as such but still a roller would be classed as hand painted vs spray painted (if that makes sense). Nightmare re the scratches though!  I would have expected them to send new units/doors to replace the ones you have now and then the old ones get sent back once the new ones are ready. That's what happened with our old kitchen ie the company we bought off got the manufacturer to send new ones as they had someone come and inspect them and agreed that they hadn't been prepped properly as the paint came off the edges. That way we weren't left without kitchen doors for months!

One option could be to make the sitting room bigger, than you have drawn, to fit a large sofa and creat a corridor behind the stairs with cloaks cupboard, then the kitchen on the left with island peninsular facing the garden and the extensions forming the dining/seating areas