Why not 4 chairs and a coffee table and that TV needs to be somwhere else in fact I would probably put the T,V in what you call the sitting room and use the space with the fireplace for the sitting room I never like the 2 things in the same space or at least remove the shelves from one side of the fireplace and put the T.V there on an articulating arm.

Your sofa should be centered and, at least the front legs, on the rug. Then, I'd put the 2 chairs with the round table in between, across from the sofa. The space between the windows could handle a chest and a decorative mirror or a piece of art.

I would first of all get a different rug that incorporates the green of your nice drapes and some other brighter colors, since your space now looks lifeless and very dark. The coffee table coupled with that couch looks heavy and ponderous, and a glass and metal table would create a lighter, more cheerful look. Your rug should be large enough that at least part of the sofa and all other furniture is on it. I would have both of the chairs facing the coffee table and sofa with the small table between them. I would put two paintings on the wall next to the front door for added interest, and add some colorful pillows to that dark sofa.

Nice house and such a pretty fireplace. I would let it be the star and see if the tv fits in the bookcase.

In the sitting room, have the tried pulling the two chairs in closer to make more of a conversation area? Or how about trying them across from the couch? No one wants to sit in a corner by themselves.

Please the most useless pieces of furniture ever invented are chair and 1/2 I have no idea what the purpose of those were even before they becamse a fossil

Looks like you have enough room at the front door area for a nice round foyer table and it will help fill out the expanse of floor. Coffee table is too big for the sofa. Does it work better with the sectional? New rug is needed. Maybe that one will work under the master bed. Group all the seating pieces within 18" of a new coffee table. Is there anyway to turn the sectional so its back isn't the first blockade people see when they enter the front door?

Is this an older home that used to have walls until someone decided to “open it up?” If so, how about putting those walls back? :)

How about a console table perpendicular to the front door to act as a foyer table? Then move the sofa to the other side of the room backing up to the new foyer table. The two chairs could be moved across from the sofa with the small table between them.

Your second picture of the sofa and table just looks like a black hole. I think some lighter pillows in the colors of your artwork would help. Also, something light on that table. Bring the two chairs onto the rug facing the sofa. And you might need an end table. Nice room.