You will have to probably redo the shelves completely. Looking at how they are built you cannot just remove the middle to put the TV in. You may be able to put some support under the shelf that will be just above the TV....just consider this. I would paint the inside of the shelves a fun color- cobalt blue or burnt orange maybe. This will give you a great backdrop for your things and keep the TV from becoming a black box on the wall. It's a great space!

Perhaps a large round table might mean a rug is not at all necessary. It could be a metal tray table, or carved wood like Rebecca Mitchell Interiors illustrates. Ideas also to consider, using multiple tables can be found at http://www.houzz.com/multiple-coffee-tables. I also agree with comments above that some color is needed on the walls. You could then hang round mirrors, or an unusual curved shape like RMI shows above.

I'd suggest dark red curtains if you need curtains at all -- the windows are beautiful as they are, and I'm not sure whether some kind of blind might not give you the ability to darken the room when you want to. On the wall, if you are real fans of any movies or TV shows, three big posters would be fun. Otherwise, I would still suggest using three pieces of art there of that size, all equal in size and somehow relating to each other. Three floral works, or three works in the same style, perhaps. I think a large plain textured rug in a light neutral from one of the cushion fabrics would tie the space together well. You might also consider a lovely low coffee table on the rug to lay out your snacks and drinks for serious media nights.

Anita Vitrified tiles by themselves do not particularly allow the walls to breathe, and hence are prone to cracking. That being said they do not collect moss either. If you are however set on using these tiles, I suggest you use them in a mosaic fashion, where smaller tiles or broken pieces are used. This will allow the wall to breathe, though the moss collection might be more due to the greater amount of grating.