Yes, too busy to do a teal on teal damask BUT I would consider a cream tone on tone damask. The stencil could be in a gloss to have it be subtle but noticeable.

I would take out two of the middle framed art near the center of the hall and add a large mirror. At the very end I would do some sort of single panel wall paper mural. And then, depending on the style of the rest of your home an interesting stand on which will sit a single vibrant colored vase with something tall and sparse. Or, a floor to ceiling mirror while keeping the continuous wall of art.

What's your bedding? I wouldn't select wallpaper without already having an idea about bedding. You may select something you can't find anything that works with the wallpaper. This wallpaper will work with different colors of bedding. https://www.thibautdesign.com/catalog/product/details/product/thai_ikat_t4951/material/wallpaper/colorway/apple_green_8/ You could also use pattern on the window covering instead of wallpaper on the walls.

I agree--thought this might be a terrible, truly dated install, but there's nothing here that couldn't be lived with and worked around for a time being. Since your wood isn't deeply grained, it almost has more of a maple effect - which is far less honeyed orange, and the millwork is classic, so can feel timeless with the right tones involved. First, I'd recommend waiting until your new furnishings arrive, and I think once they do, you may find that it's the almond effect of the base wall tone that's setting the color temperature to "too warm" for your tastes in this space. A more saturated grey and a true, untinted white in here on flatwork could help reset the effect of your wood trim in these spaces and match your stair spindles as better neutrals in the space, along with some updated door hardware. This space isn't at all beyond hope. One thing I would consider are dramatic drapes to frame your feature wall that stack off to the extreme far corners and run full double-height. That would fill the visual space left to each corner on the wall and visually center the window orientation, anchored by fabric fold framing to coordinate with your new furnishings. Won't be cheap, but will highlight what's clearly intended as a wow of a central feature wall and first impression in the house. Cheers!