IMHO, this does not look good at all. I would not except this solution. It looks like you just slapped up a piece of molding. It needs to be integrated more with the existing chair rail and base molding. If you move it over to start under the chair rail, it would be too close to the boxed out trim. If you want it to look like it is meant to be this way, he really needs to move the trim under the chair rail and shorten the width of the box so the spacing is the same as the distance between other boxes. Also, the trim piece should not stand proud of the base piece. You need someone that knows how to rework this to look professional.

I like the new chairs you are considering with your others I would not do kilim or juts in that space with those cahirs but maybe look for a great deal on a traditional persian rug and a round coffee table . IMO go for that old library look and I would for sure do drapes not blinds and remove what looks like a fake plant too. You will need to add some lighting for sure if there are no pot lights and just try for the ambiance of a library you are almost there .

Living area is 24 ft. W from window to front of inset wall. Hallway entrance to bar area is 27 ft. L. Where to place 55" TV? and sectional 120" x 95" Placement /Color/Size of area rug to complement room Where to place 2 oversized chairs OR 2 smaller chairs?

I would do 2 ghost chairs and then get some art on the walls hopefully with a bit of pink somehwere in it a nice shallow ledge under the art and lose the two skimpy plant stands .