This will help get some light into the middle of your space. http://www.westelm.com/m/products/overarching-floor-lamp-antique-bronze-w890/?pkey=cfloor-lamps You could also do end tables or a console behind the couch and place table lamps on either. It doesn't look like you have any seating near the edge of your space and your existing lighting seems to be positioned at the edges of the room. So I'm not sure if sconces would help much.

Two matching mini-chandeliers could work, but you have a vent and other holes in the ceiling and would have to work around them. If you can enclose a couple of the holes, you could place each small chandelier an equal distance from the center of the ceiling as it corresponds to the center of the table. I would suggest a large, square framed mirror over the fireplace and a large tapestry or other form of wall art on the back wall. By having two chandeliers, the wall art could be seen between them instead of being blocked by a single light fixture.There is a lot of plain space, and white-painted bead board wainscoting could break up the large, plain space and bring a different texture and color to the room. A solid-color area rug inspired by a color in the wall art or tapestry could help tie the color scheme together.

Hi Rishab, You can avoid creating 4" false ceiling and create 1.5 / 2" false ceilings just to let the wires hide and run within the false ceiling. I will not recommend conduits or exposee ceiling unless you wish to do a rustic interior design. You can go for Surface mounted lights and track lights. They are beautiful and are available in different shapes and sizes too.

the more gap you have the more light will diffuse. the beauty of cove lights comes from that gradient. if you have a small space then that look won't come. additionally, refering to your previous post, it will also be a place for pests. If you want this design, I would suggest you go with an LED and cover the gap with an acrylic cut out. that will give a nice effect. or create two levels, let the flat part stay where it is and make the circular one a recess