Hi, your home looks pretty good, you have done a lot on the interiors. Coming back to the question, yes, you can add a wallpaper behind the television, go for a textured wallpaper as it will create a compliment to your television. As you have decorated with wooden elements, you can go with a bookshelf on the wall. And, there is one more thing which will be a simple addition but will look perfect and that is an antique wall clock. An antique wall clock will make your wall look great without any fuss.

The retaining walls are what I like the most. IMO you need to identify what it is you don't like. Is it the style and/or colour of the retaining walls? Is it that they are just too overwhelming for the space? Is it the proportion of hardscaping to greenery? Is it that you don't like the space but are not sure why and thought that because the retaining walls seem most conspicuous they must be the cause? I am not saying that because some of us like them you should also like them. Each to their own. I agree with the concerns that the retaining wall would have too much movement for rendering to work. You would need to remove the wall and replace it with something you like, as suggested above. But it's a big job so I think it's worth having a good think about what exactly you don't like about the space. I don't think the pavers go well with the walls. Perhaps replacing the pavers would work? (What colour is the house? I assume it is to the right of the picture?) Perhaps growing more cascading plants would soften the appearance of the walls? Perhaps growing something taller to hide the fence would make the space more pleasant? Give it some thought. If you decide it IS the walls you dislike you'll probably have to replace them.

Many years ago, we had a friend that wanted to make his whole house out of exposed concrete with curving walls................. wonder what ever happened to him?? As for me, ah, no!

Not for me, I find the concrete floors too harsh, the one good thing about them when they go off trend easy to cover with something else.