My humble view. I'm not vastly experienced in this field but have gone through the sort of problems you may have. My final solution was radical, involving lots of acoustic foam and a digital equalizer, but you should be able to make good progress without resorting to all that.
You could put a sliding wooden door on the kitchen opening which if it locks in place rather then just hangs loosely should help.
Is two feet the recommended height of the stands for your speakers? Seems a bit low to me. It's often said the tweeter should be about ear height. Your speaker manufacturer should make some recommendations. Perhaps you could use some temporary stand creation to use for your initial set up trials so you can vary the height a bit.
As the furniture can't be moved, the only way to try and get a good sound at your listening position is to move the speakers about. It may be that once you find the best location for the speakers that they will be in an inconvenient location. All I can suggest in that case is to mark that position and move them into place when needed. There is plenty of info on the net about 'speaker positioning'. Here's one source:
http://www.gcaudio.com/resources/howtos/speakerplacement.htmlIt may be that once you have it right the speakers aren't exactly symetrically positioned - that doesn't matter too much. If you both listen at the same time you will have to check that the music sounds good in both seats.
What we are trying to do here is get the bass right. Particularly we are trying to stop it being boomy, the most likely problem.
If after lots of faffing about you still can't find a good location to give you satisfactory bass, and it remains boomy then maybe bass traps should be considered, or some sort of equaliser. You will need to identify the problem frequencies which likely are associated with your room dimensions.
Once the bass is sorted you can look at the higher frequencies where problems are likely to be caused by reflections or absorptions. Obvious problems would be the coffee table (i'd remove it for listening if you can. I notice you've got carpet there, which is good), absorption of sounds from the left speaker by the chair but reflection from the right speaker off the wall (first reflections). There may also be reflections off the back wall, then off the front wall and tv screen (secondary reflections), but I think this looks less of a problem. The side wall reflections/absorption are the worst here and you would need to make them symetrical. Probably best would be to have some sort of absorbent material in a similar location to the chair opposite.
Moving the speakers round is a frustrating and time consumming business but once you get that right, the rest is relatively easy.
