I dont think a sectional is right for this room. you would get a lot more function out of sofa and chairs. Leave the tv on that wall but center it too the wall. pull the sofa off the wall . try centering it to the fireplace wall first. then try centering it to the tv next to the fireplace. you need to get used to the idea that the couches do not need to be on walls here.

well, you could always remove the chair rail. but yes, if you paint the walls, you'll have to pick the same color to carry out through those adjoining halls I think Pale Oak, , Smoke Embers, Nimbus, or Light pewter would all be lovely in your space. I'd also hang a nice piece of art here to tie in the pale aqua chairs, maybe to some pillows on the sofa w/those colors. the fireplace/mantle is way too traditional looking. I'd remove everything. if you want more Boho, try some zellige tile on the surround I love this selection^ or a cement tile with natural wood mantle or, do more of a modern surround w/a marble tile at the very least, do a diff surround w/out the fluting

Nice save on the fireplace!!! Would love to see a new photo taken farther back in the room :). Here are a few inexpensive things that you could do to brighten the space: the valances in the kitchen are very dark and the ruffled style looks fussy. Perhaps you could switch them out for DIY faux Roman shades in a print with a light background that brings in a couple of the colors you’d like to use in those two spaces. Maybe bring in a fresh green color on an ivory background (along with another color you like - yellow, aqua, coral) since one of the only colors you are currently using in the space is a plant. Hang the shades all the way up near the ceiling so they don’t visually lower your ceiling and they don’t block any light from the windows. Re-cover your counter stools in a solid color vinyl to match one of the colors in the shade fabric, even the light background color of ivory etc would brighten up that area. Exchange the dark throw pillows on the couch for some pillows with color. Put a colorful large canvas art piece over your fireplace. Perhaps the mirror could be relocated to above the sofa. Right now it is not reflecting light from a window, a chandelier, or anything attractive (and it is colorless). If it were over the sofa, at least it would reflect light from the opposite window. Move the long skinny iron wall art that is currently next to your patio door to the right side of the TV to balance the shelving on the left side of TV. Could the back walls of that shelving area next to TV be painted in your new light wall color? Maybe even paint the entire shelving and drawers the same as the wall. That would lighten them visually. Remove the two clocks or whatever the small round items are from the TV wall and use them elsewhere - they are not adding anything to the “composition” you have going on there. Perhaps you could add a Frame TV to your wishlist - it would do a lot for that wall. And bring in a couple more plants :).

It seems placement could work centered or offset, but without the sconces only. According to your sketch, the sconce is too close to the hall. If the artwork is offset from the table, you have the balance and massing from the sideboard, so picture yourself sitting in the family room. First, you probably won't view the art perfectly associated to the center of the table. Then, if you see the artwork not centered on table/chandelier, that may be ok because the visual breakup with the sideboard may balance the entire view. And you've drawn like a long 6'+ piece, so it may conflict with that 4-gang switch box there anyway. But, I would probably just eliminate the sconces as IMO it detracts from the art anyway, and limits you in flexiblity for a different sized piece in the future. Then you can play with a centered or offset location upon hanging. I think either could work. Same logic I would apply to the sideboard, whether it can be centered or offset from the table.