I love your home and your furnishings! I could happily move right in. I have some thoughts about what I might do in the space, so I am going to throw them out at ya. Keep in mind that of course how things appear on a computer screen might be very different than how they are in real life, and most importantly, it is YOUR home and you have to live in it the way it works for you. What I see now is a living room in which almost everything furniture-wise is on the same 'horizon', except for the one secretary(?) or cabinet. All the color, all the warmth, all the interest, is pretty much at the level of the back of the seating or below. The room doesn't feel warm because from about waist height up, you have plain white walls and white drapery. The second thing is that you have all kinds of interesting chests and cabinets around this room, in your hallways, and in your other rooms that we get a glimpse of in this thread. But they are just stuck one per wall section around the room - no connection, no relationship, and no real sense of purpose. The third thing is that the arched window that you say you love, that has a good view, instead of being featured, is blocked by the largest seating piece you have. So, here we go. I would like to see the couch facing the arched window. Opposite it, centered on the arched window, the mission chair and ottoman by the fireplace, the butler table moved in between, and the rocker on the other side. Or, face the couch to the fireplace, and put the rocker on one side of the fireplace, the chair and ottoman on the other. If you do that, consider turning the rug so the long side runs parallel to the fireplace. In fact, you could try that with either seating arrangement. I would love to see an iron coffeetable, or something with a copper hammered top, and round, if you still want a coffee table. I think the butler table could sit nicely with all sides up or down by the chair near the piano, if you don't use it between the chairs in front of the arched window. I would move the piano to the end wall opposite the fireplace. Place the upholstered doggie chair next to the piano, on the side closer to the corner. Put the floor lamp between the chair and the piano so both can benefit from the light, and you can create a nice reading space there, removed a bit from the central seating. Since you have so many cool chests and cabinets, I am wondering if you have two that would fit in the arched window niches on either side of the fireplace? They don't have to match, just compliment one another. A pair of low bookcases would work, too, but you seem to have chests around that could work and not cost a dime. I would think about getting rid of the curtains in those niches, and replacing them with wood blinds or woven woods that compliment the wood tones in the room. The white panels don't do anything to make those charming window niches an asset, imo. If you had a chest or table that would work behind the mission couch, that would be great. A lamp there, a pretty plant, or a great piece of pottery. I would think about moving the secretary/cabinet to the entry or another spot. I don't think it works well in the space, and doesn't let that nice piece shine as it should. The white drapery wouldn't be my first choice, but it isn't bad on the arched window and the one opposite. Personally, I would rather have something with more color to bring the eye up in the room. Or, working-louvered shutters in a warm wood stain that could close over the windows or swing back against the walls on each side. The fireplace wall. I know the little niche is fun, but I am not sure it really works there. I would be inclined to add a thick wood mantel, at the height the shelf of the niche is, perhaps that could sit over that shelf lip and hide it. Then put a big piece of art or a mirror (which would bounce light around the room) that would hide the niche. That way, it would always be there down the road if you decided to use it. I would love to then see the area below the mantel in a tile, something with an Arts and Crafts design in some of the tiles, the rest just in colors. Be sure to leave the stairstep design around the firebox, tho. Then paint the area above the mantel in the same wall color as the rest of the space. As for the wall color, I would be inclined to keep it light. Something like SW Interactive Cream, perhaps. Then start looking for artwork to use over the piano, on the mantel, on the now empty wall spaces where the secretary and the chest on the opposite wall once sat, as well as where the piano was.

As far as arranging furniture with the columns, I would tend to ignore them and group seating around the fireplace. You are always in good company with a more flexible 3-seat sofa and two upholstered armchairs (or swivels.) I think a sectional will just add another complication to the space. What is opposite the fireplace? Are there any floor outlets near the columns or actually in them? Is there any electrical wiring in the bulkhead above them? They might be interesting if lighted. You could also install some glass shelves between the two that are near the exterior wall. Lighted from the top, that would be a great display for something like colored blown glass. As for the lighting, you can find less expensive variations on those. Scaling them for your room size will also lower the price somewhat.

I would move the desk to face entry with some art above. Sofa in front of window with 2 chairs across from it, a coffee table between. Facing the fp, if you wanted add’l seating you can look for an upholstered bench which will keep things feeling open when you walk in. Flank the fp with 2 consoles or small chests if you need storage. Place lamps around the room for lots of ambient light

Here is a different view of the whole room. Don't mind all the misc stuff, we just moved and still have stuff everywhere! The shelves on the wall will likely be more for pictures, etc. I am also considering a sofa table behind tge couch that would offer storage for things I wouldn't want seen. Including a few pics of what I'm thinking of for that as well.  They are all about 12" deep so hopefully not to bulky for behind the couch.