I would look for a dresser with high clearance underneath that could still go in front of the baseboard heater. I see several on West Elm. This one comes in wood or white and dimensions say 6" clearance. https://www.westelm.com/products/mid-century-6-drawer-dresser-g815/ This one doesn't specify the clearance but looks very tall. https://www.westelm.com/products/van-7-drawer-dresser-h6159/

If you do drapes, you will need to keep them within that deep frame so the baseboard heat doesn't get trapped under them. The hems would stop at the sill. Or you could do floor length drapes that are kept open all the time. This is to simply trim the window if you feel like shades alone are too plain. I've looked into top-down cellular shades for my large windows and determined that they would be too fussy and hard to keep straight. They break easily. The bigger the window, the more annoying they will be to deal with. Besides, top-down is more like for homes where people are trying to get some privacy from the street, not a problem in your high rise. For you I recommend room darkening roller or honeycomb shades. (or blackout if it's east facing, but otherwise I don't recommend blackout if you don't need it.) Don't get the "pull down" style. Get the ones that can be operated with "continuous loop" cables, or even motorized if you are feeling fancy. If you need to filter the light (like to keep the room cool), some people get two sets of shades -- one opaque, one sheer -- and install the the opaque ones in front. Your frames appear deep enough for that.

I’m a bit challenged trying to visualize this room as a whole. I think that how much use for going in/out the sliders needs to be factored in. The front slider next to the window is the most challenging IMO since there’s no room for any window covering to stack completely off the glass on the fixed panel side of slider. I agree the same fabric & treatment should be used for all windows. I think I would hang separate drapery panels over each window. For the front slider & window I’d use the same length panels for both slider & window for a better look when closed. That slider - I’d have drapes that open in middle & pull to each side. The corner fixed panel will always be partially covered with the open panel on left. The drape for panel that slides should stack completely off the glass so that door handle can be easily accessed. The window would be traditional drape open in middle & stack completely back off glass on both sides. Two rods for each window - sheers on inside rod & drapes on outside so the 2 coverings can be open closed separately. When closed, this wall would appear as a complete wall of drapes. As for color - don’t know if you’re wanting dark blue or thinking that’s room darkening. Room darkening drapes are available in many colors. Slider in dressing area should have same treatment but sounds like with 16” space on each side the drapes can stack completely off the slider on each side. Whether that slider has sheers or not depends on the privacy issue. Maybe only drapes on that one - no sheers.

I think wallpaper could look beautiful in there. It is overwhelming choosing one; I’d just look for as many inspiration pictures as you can find … see what styles/colors/patterns/etc you’re most drawn to and imparts the feel you’re going for. I’m not suggesting any of the ones below specifically, just showing some styles with sort of similar headboards. You have a blank slate and could use just about anything. If you decide you want to do paper, choose it first and work the room around it. Tons of possibilities! You could do grasscloth, too, if you don’t see a pattern you love, but would like texture. ETA: Don’t be afraid to mix patterns for a layered look if you’d like — you don’t necessarily have to use solid bedding if doing a patterned paper.