I think a cocktail table labeled as such will be the correct height for the sectional.....

What does the 4th wall in your room look like? Is it possible to rearrange things? Give it a quarter turn so that it is no longer in front of the windows. In other words, one section on the back wall and the other section would be where the TV / console currently set. The TV could then be on that (unseen) 4th wall. I also think the TV is mounted too high.

just a few ideas that I'd suggest. a plant in the corner where that little bench is. I posted two diff types, either would work. I gave you a side table w/a lamp on the other end. I like the idea of a pouf in this camel color to warm things up a bit, or do a stool or two placed in front of fireplace. I also like these shelves between the two windows. ( I don't know what furry dog is going to do with these,,,maybe have the toddler stand on his back?? lol. hang them well out of reach and they'll be fine. I'd put a few small plants on them. This will eat up that middle space) You could also take these teak decking tiles and attach a plant/pot onto it, and hang two of these between the transom windows. if you want a bench, do something like this in the wood. all of those neutral gray tones make everything seem very cool. add some wood and some texture to warm it up a bit. over the back of sofa do a cool piece of art don't hang them too high. (your tv is hung too high btw. ) and a rug for the sofa area A jute one would work too for the dining area, you could also do this jute rug like shown. for the wall, I'd do another piece of sizable art to hang on that one wall. This one has a larger wall, but look at the black and white picture. basically the same size of yours. you want something this big. Or, do a shallow buffet or console w/a mirror over it and some greenery, like shown here.

IMO if comfort is a big issue then go sit on sofas until you find one you like , there is no way to guess comfort from a picture.