Actually your living room set up looks like it will work well. As Nrchy suggests the speakers will sound better if the front of the speakers is out into the room (some 4 to 5 ft I would suggest) and if you can do that you might get away with minimizing reflection problems off the windows behind them with out doing anything. In a similar set up I just put a couple of large/tall, easy to care for, plants.
You also have some potential problems with reflections from the side walls, especially the glass windows. Something you can do to minimize these reflections without adding a lot of audiophile treatments, is to simply toe in your speakers so that the axis of the speakers crosses in front of the central listening position. This also accomplishes another important thing considering your proposed uses. It creates a much larger central listening position.
Assuming that you are using classical cone/dynamic speakers when you position the speakers firing straight ahead you not only have to deal with 1st reflection points the central sweet spot is the only really great stereo listening spot. If you move to the left for example the stereo image moves to the left. If you are sitting directly in front of the speaker most of the sound seems to come from that speaker. If the axis' are crossed in front of you and you are sitting, for example, in front of the left speaker, you will hear the left speaker sound well off axis and at a reduced level. You will be hearing the sound from the right speaker on axis but from from a greater distance so it will sound more balanced (with the sound from the left speaker) and present a reasonable center image and stage. It ain't perfect, but it works quite well.
That is what I have done in a 13.5x19.5x9 ft room with speakers with the fronts 65" from the back wall, 18" from the side wall, and the central listening seat 9'6" from the front plane of the speakers. With carpets, bookcases, and ordinary furniture, I have minimized reflection problems with out audio type treatments on the walls.
FWIW, but it's worth trying.
BTW, different speaker types can present different opportunities as well as liabilities, so consider that if you haven't already selected your speakers.
Hope that helps a bit.