Might I suggest a more contemporary picture frame mantel with mosaic stone tile between that and your firebox? Love the near craftsman window shapes flanking the fire wall . . . use the height on both sides, / shallow shelves on one side can visually frame a swing arm for your television and give real storage on the other side.

Try the TV where the sofa is now and float the sofa perpendicular to the fireplace where you currently have the big chair. Perhaps the big chair can then go where the TV was for a quiet spot for one. Or even better, pull the loveseat off the wall and put the big chair to its left flanking the fireplace.

Depends on how you want to style it, but I think this would look lovely and make your room feel nice and cozy.

I'd love your advice - Where would be the best placement of my appliances, sink, oven etc? I would love to have my sink under the window - do you think it could work?