Something like this would be great!

There is a lot of paste and size residue still on the walls. Washing and scraping helps but it still feels like it's there. Would a good sanding be sufficent or do I need to wash all the paste off before painting?

What a lovely space! I would suggest an earthy deep green on this wall and possibly repeat this hue somewhere else in the space….either via cushions or art or another wall. the lime green pot does not work in this earthy natural space….it’s too loud. Maybe paint it the same green as wall. Keep the space calm…..timber, rust, deep greens

Have you tried the Dulux Visualizer. I have used this personally and found it to be quite helpful. It allows you to take a photo of your home and then experiment with different colours to see what works best. Another option you might consider is the Sherwin-Williams ColorSnap® Visualizer app. It allows you to upload a photo of your home and then try out different paint colours and combinations to see what looks best. I hope this helps!