This room is an embarassment of riches! How fabulous to have such a gorgeous space with those high ceilings and interesting details. As mentioned below, I wouldn't stick with a "minimalist" approach in such a feature-rich, 1928 space. Be a bit bolder and find a style that you like. The twenties brought in the arabesque. Why not draw the eye up to those lovely high ceilings with a vintage chandelier? (Look at curtains as an opportunity to soften the space and bring in color.)

Deep brass, milk glass shades, restored antique chandeliers - all will enhance your home’s age.

Just having a little fun with the decor for this room and adding some furniture. Ai has widen the room a tad and added a few features that don't exist, and it may not be the style that the op is wanting, but it's fun to think about what the room could be.

I can see why you don't like it---I'd rather see a mitered joint than a 90 deg. cut like that. It's definitely not pleasing, but it would at least be on both sides and symetrical. It looks like sloppy joinery. I'd try to find a solution. A shorter crown? Best of luck!

Add an upper row of cabinets to balance out that hood ab give you more storage.

How high is the ceiling? Is it vaulted? To me, cabinets that don’t go up to the ceiling look awkward and cut off. The hood protruding above them emphasizes this awkwardness.

You seem to be asking a style choice. Moulding is a traditional, looks more expensive, and seems more in keeping with your house. No moulding is a clean, less expensive, more modern look. Personally, the off-center doorway would irk me. I'd try to even it up, if possible---depending on the view from the other side. Have you got a pic of that side? Is the reason for the off-set wall structural or because there are pipes?

The millwork profile, continuous 2 part crown, door panels, cabinets, etc all point to a cased opening (right now it is not cased, it is drywalled) that should be bespoke around the entire house. It is a no brainer, add the return on the other side and case the opening.

It has nothing to do with what appears expensive or personal taste, it has to do with consistency in design.

I like the idea of making the opening centered on the wall by building the left side out a little, and then adding moulding around it. Gives it a finished look.

Yes! Look outside your window. Nature is replete with all colors. Just pick a third color for your 10% ish complementary color from a rug, curtains, wallpaper, etc. that you like. See examples like wallpaper and fabrics from William Morris's art: https://wmgallery.org.uk/

See also, wallpaper examples of the strawberry thief: https://www.janeclayton.com/morris-co-strawberry-thief-wallpaper-indigo-mineral-212564-us/

Or see examples as found in pillows at Rejuvenation: https://www.rejuvenation.com/shop/decor/all-pillows-throws/

I love red or a deep pink as another color with blue and green

I have blue-green kitchen cabinets and LR ( open concept layout) is teal, green and magenta