How big a TV do you have/want? Will it fit next to the fireplace? You might want to change the fireplace surround and mantle to get a few more inches. Filling in the niche with drywall might help, or can you enlarge the niche?.

A console table behind the sofa might help define the spaces and potentially add some storage.

Regardless of whether you reno the cabinets and countertops, I agree with new lighting. THAT will make a ton of difference to your space. On my screen everything reads a bit 70's avacado green and has yellow tones to it. I think in order to brighten it up you should go cool bluish tones. Not gray but a cool white.