We have lots of arched doorways in our home and none of them have any molding. I'm not sure they would look right with molding. A 90 degree angle on the drywall/plaster makes it look clean and nice with matte/flat paint. What did you decide for flooring?

That is pretty, flyleft. I think the reasons it works are the very high ceiling, the continuing brick work on the wall surrounding the mantel, and the raised hearth. Although that vertical brick makes me wonder about maybe doing stone of some sort in a vertical brick pattern instead of the square limestone tiles. Too trendy perhaps?

I would also consider ceramic based lamps, however you can consider a brass floor lamp. These are not expensive floor lamps from Target. Lamp Shade is separate selection. This one below from Target Ford Collection All these table lamps below are also from Target and might be worth considering.

Regarding the rug, the color is great but a touch too traditional in design. No matter what you choose, you‘ll be tied to It. If it has more colors, you can go bold or use more subdued shades when you tire of a look.