I think you've got some good ideas. I've seen some nice rooms with wallpaper behind the bed. As long as the wall is correctly prepped and it's in your budget - go for it. When/if you want to change, it should be easy to remove. If you're going to do that, I'd choose bedding with little to no design. Clean and serene. I like your tulip table and also the acrylic piece - if it's the correct height. It may not be in your budget, but I love the floating shelves that decoenthusiaste posted. We can't see your window coverings, but I really like having room darkening treatments in my bedrooms. I used to frequently visit family in Texas and my room was east facing with shutters. The morning light was terrible.

Those Pax wardrobes are fabulous storage options. I'd go with white, for sure. The Pax didn't work in our bedroom but I think it's partly because they were at the entrance of the room. Surrounding the window as you have it in your layout would work heaps better. They look great in Lyfia's pics. I'm also short and feel claustrophobic with tall furniture so that's my bias.

I fully agree that you don't need to fill all spaces. This area is a candidate for doing absolutely nothing. Obviously, a lounge chair or any chair would ever be used in this setting. However, as I look around the room I don't see an area where you can throw a robe or put on socks. This is why I suggested a small bench.

Your furniture choices are going to need to do double duty. Have you room for a comfortable chair? Storage ottoman? Your cupboard is going to have to work hard, maybe some low drawers that will fit inside the cupboard. Then you can have a full length hanging section, with shoes beneath, a short hanging section (shirts, jumpers) with the chest beneath. When looking at bed frames, go with something that will allow you to use the space underneath for storage.