My parents' old house had a wonderful oak front staircase that my six siblings and I used to race up and down, taking them two or three at a time, with only a casual hold on the railing. I don't know how we managed to never slip or fall. Now, the timber backstairs were steep, and had narrow treads and were poorly lit. We NEVER ran up or down them, but held tightly to the railing and hoped to heck we managed to stay upright. As an adult, my previous home had carpeted stairs, which I slipped on (wearing socks) and fell down twice, though thankfully I was closer to the bottom than the top. My current home has timber stairs with three narrow stainless steel runners stood on edge and inset horizontally across the front of each tread (this is supposed to help reduce risk of slips). I doubt I will get over the anxiety of taking another tumble, so I never go down them wearing socks, and if barefoot, I hold onto the railing for dear life and take it nice and slow. So far so good.

I've just been looking at your colours, I think the Dulux Dieskau would work the best with the other colours you have to work with, choosing colours is such a personal thing and I know it can be really hard to choose and hope you make the correct choice. Oskuee is right, a paint job can look terrible half way through so you need to make sure you finish to get the proper look of colour. But the biggest thing to remember is it's only paint and it's the cheapest thing to change so if your not happy with the colour you choose you can always try something else. Happy redecorating :)

Keep it simple if you are keeping the carpet in the dining and sunken lounge, you would just have to shampoo the carpet under the dining when it gets grubby. If your carpet is in good condition you could Keep the carpet in the sunken lounge, tile the rest. Take up the carpet in both areas and tile. Then have two large carpet rugs made from the old carpet for under the dining and in the lounge. cheers

The blue you add has to be very soft and beachy and I find looks stunning with brown but as I said HAS to be kept soft would work as well with the earthy beige/sand tone as well as the white, once again it has to be something you love and are happy with so bring home swatches or keep an eye on pinterest as well as Houzz pics to see if you can find similar, it's your home and space it has to feel like you and make you happy perhaps even get some paint swatches to play about with...I know changing things is a big decision so good luck again.