I agree with bringing the chairs in from the corners just a bit -- it will make the room seem larger; but I think the height of the prints is just right -- it makes that squat ceiling look higher by having space above the chairs, and you do not want to close this space. What's wrong is that they are too far apart -- balance the space between the corners and each print ~ in this case think in terms of visually-balanced fifths: wall-print-wall(including decal)-print-wall. It's the faux fire that's brining this room down (have you tried lowering it to the floor?), but Junipergirl is right ~ the room needs to be anchored, and the perfect rug would do that. I too would usually choose something traditional (that's my personal taste), but for this space, to harmonise styles, I would suggest something more modern, and something with texture as this room is texturally very flat. A shaggy white rug (seeing your husband insists on keeping those white walls, and in a space this size I am inclined to agree with him), with touches of the rose-pink echoed in the prints would anchor the whole scheme beautifully. I agree that the finishing touches of a table-lamp (think of that classic 'Ritz/Savoy' pleated shade, in white, with a gold-tone pedestal to match the print-frames, possibly on a very light-looking round Deco occasional table), and an indoor palm - something texturally variagated, not smooth - and I think this room will work very well ... it's much better than you seem to think Gov (I feel very Cockney saying that!), and all the features - except the heater - are good and work well together.

You could consider reupholstering the dining chair seats in a contemporary black fabric or replace any existing chairs with contemporary black ones (think metal). Add in some art or photos with black frames around the dining table too. :)

If you have long dinners, they are not particularly comfortable. I gave away a set years ago. Ok for quick meals.

Google Annie Sloan Chalk Paint. It's the best chalk paint. Just wondering...why are you actually wanting to renovate the table - is it in bad condition that we can't see? I agree it needs to stay a dark colour. To be honest, I would leave the table as is and spend the money on some drapes for the windows. At the moment it all looks a bit stark, but that's just my opinion from what we can see in the pic.