Do you need the fireplace? It would be a great help as a room divider, but in the locations you have it, it really can't function that way. I'm assuming this would be a gas fireplace. Can it be very modern? Or does it have to be more of a traditional fireplace? Some modern fireplaces can be small and can be placed almost anywhere, which may work for you. Part of the issue is the space, once you remove the traffic area, is really a square which then needs to be divided in 2 for the 2 functions. That leaves you only about 9' or 3 meters for each function which is pretty narrow. Plus you need traffic area to get from one function to the other. Candice Olson has done some interesting dining/LR combos. Perhaps one of them will inspire you. Given the size of your area, look at the rooms where she's done a built-in banquette for one side of the dining area as a way to save space.

A round or square end table big enough to provide useful space for both sofa and loveseat would work, with a large lamp. I have a couple of live plants under a similar mini-split ac unit and also near hear registers and they don’t seem bothered as long as i don’t let them dry out. Some pillows that pull the color from the very pretty rug would be nice, maybe the pink? Or green? Drapery panels can often make the difference between a comfortable room and a cozy room that feels finished IMO. You might want to check out curtains in linen or cotton from Ikea or Target, they’re quite inexpensive and look decent for the money. Mount the rods near the ceiling molding and have the drape just barely touch the floor. You may have to shorten, they make iron on tape that make it easy to hem without needing to sew. A cream color would look nice with your gold-beige walls. Mount the rods wide enough to push the drapes back off the glass for maximum light and views when they’re open. You may never need to close them as you have blind for light and privacy control. hope this helps.

I think the piece the TV is on would feel more at home in the basement with the chunky coffee table. Your home looks to be more contemporary in style except for the stair railing and the big empty display/bookcase. Do you have the budget to remove the built-in? That would give you some wall space for furniture and art. What is the exterior style of your home? Can you pull off a contemporary interior design and not stray too far from the look of the house outside? I don't think the DR is large enough to add more furniture there. I suggest a great piece of art and a rug that is 36-42" larger than your table top on every side. Pull the same colors into the LR with big art on the wall opposite the FP and above a 3-seat sofa where the built-in is. You can do another rug in the LR that is similar in style and color to the DR rug. For example, here are two navy rugs that could work together. The top one picks up your wall color, and the bottom one picks up on the fireplace stone.

The table top in your inspiration pic caught my attention. It's not the usual furniture showroom table top. I really like this cedar "countertop" and was wondering if something like it might work as a table top or as a top of a rolling cart island that could work as kitchen prep space and/or guest dining if not as a table. http://www.devoswoodworking.com/designing-wood-countertops/wane-edges.html Legs could be bought separately. https://carolinalegco.com/products/x-metal-table-legs-set-of-2-modern-industrial-legs-custom-sizes-available?variant=32186224640097&currency=USD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&utm_term=&utm_campaign=DR_PLA_Smart_200%25&utm_source=adwords&utm_medium=ppc&hsa_acc=7051262680&hsa_cam=9915659242&hsa_grp=103137792649&hsa_ad=432122759881&hsa_src=u&hsa_tgt=pla-296303633664&hsa_kw=&hsa_mt=&hsa_net=adwords&hsa_ver=3&gclid=EAIaIQobChMI6p_wwNPU6gIVgbbICh0T8w-jEAsYAyABEgIkX_D_BwE