You have a very unique space. The one thing to consider there is colour. You have orange/yellow wood cabinets, and I believe from the photo the carpets are taupe/ with a slight pink in them? Once you know the undertone in your carpets if they are staying then you will have a better way of knowng what direction to go.
Does this make sense?

First thing is to go to your closet and look at your wardrobe. What colors make your heart sing? Remember that your home should reflect your personality.

Do you truly love neutral and sage green? I would paint the walls surrounding the kitchen and the ceilings in a color like Devine Stone and then paint the rest of the space Devine Moss and hang a large picture above the couch with bold autumn colors and place a few pillows and accent pieces around with the colors from the picture.

Simply Inspired Design is correct that picking the right neutral tan/beige can be difficult. Every neutral has a base color and they don't all work together. A pink undertone to the carpet or flooring will make a lot of tans look like dime store pancake makeup. A yellow undertone on the carpet or flooring will make taupe look purple and pink undertones in the tans look pink on your walls. Attaching a picture of a green and pink based neutral so you can see what we are talking about.

I love that you can order an 8!/2 x 11 painted sheet from Devine Color for $2.29. No painting splotches all over your walls and you can move them around the room and get a feel for the color in different lighting and against different furniture. Painted samples are so much better than paper. Paper never reflects the actual color.

If you don't love a neutral sage pallet, but love purple or blue or red then my color selections would be very different.

A nice screen would look good at the far end of the sofa. It would break the long view back to the kitchen and make the space seem cosier.

unless the cat killed the deer and likes to look at her trophy I would take that head off the wall. I dont think it goes with anything personally.

Remove the corpse and make a hip glassbar on the kitchencounter. Add 2 classic barchairs and a beautiful painting above the couch. Then it's perfect.

Check out Ben Moore HC111, Nantucket Grey, it's a neutral but adds color and could be used in the space. It's a soothing color you will never tire of. I have used in two different houses now and it goes with everything. I have an open concept townhouse now and this color really flows well in all rooms from living spaces to bed and bath The use of one color makes the space flow better.

Tres, as much as I would love to paint the cabinets or add walls, structural changes are not an option as the apartment is only a rental. However, thank you for your suggestions on the pictures and the lamp… the deer head is a family heirloom of my boyfriends and therefore is here to stay! Accenting the head is definitely a suggestion I will be taking you up on.

As for the carpet, it is a very basic beige color.. more of a sandy tone than a pink. We were actually leaning towards a sage color in the living room so I am happy to hear that you all would suggest a green!

Debra, thank you so much for your suggestion of the BM Nantucket Gray… i have instantly fallen in love with the color! Would you (or anyone else) suggest painting both the living room and dining area in the Nantucket or going with a complimentary/contrasting color palette for the adjoining rooms?

Because you have the deer head mount, I think you should go with woodsy colors. He would look very nice with the sage green wall. Make it a light sage tho! Maybe just do the living room and live with it for awhile then see if you need to also paint the other rooms.