The first thing I would do is buy some colorful rugs for your dining area and living area. With your dark furniture the place looks rather grim. Gray is on its way out, and you need some drama to dress your place up. Pull the couch away from the wall a little bit so it doesn't look like it's glued to it, find a metal and glass coffee table and also a low bookcase to put against that empty wall and put either a very large painting there or a gallery wall. The same goes for that area by the dining table. Since I gather you have a cat I thought of a climbing structure for the empty area by the kitchen, but then I'd worry about flying cat hair in your food. Hopefully someone else will chime in with ideas.

It looks like your entry door opens directly onto a sofa... that does not seem great. Can you post a measured drawing?

For your challenging wall backing up into the kitchen, I would get some gorgeous fabric and hang it there (you would probably need to study how best to do this with a rod on both ends at a minimum.) I like bright Marrimekko prints myself like the ones below in a museum exhibition of Finnish design.

If you are interested inFinish design: http://designcompendium.blogspot.com/2012/04/finnish-design-show-northern-stars.html 

There is an amazing tidbit about Nokia's first phone in there.

Perhaps steel shelving for behind the stove. This Crate and Barrel piece is 32-in wide, and your range is 30-in., so you would have a few inches on each side - which would look fine. I'd lean a metal or other non-combustible tray on the shelf to hide the back of the stove. Depending on weight, you might even be able to store your microwave there, if you'd rather have it off the counter.

Or this one - a bit taller and larger, and less money