That’s not an awkward space. IMO it’s just fine - adding shelves there would make it awkward. Especially shoved up against a fireplace AND a tv.

Agree^^^^ I would get the TV up and the furniture placed before worrying about that space. Also anything placed there will need to be balanced on the left side of FP

Put your furniture in and then post a pic.

Paint the bricks the same color as the mantel. Add art over. Paint the paneled door black.

Don't worry if you don't know where exactly you will place your furniture. Once you put it all in the picture you will get lots of opinions! :-) Then you will get people telling you that you should have provided measurements of the room and every piece of furniture. And they will ask for more pictures from the different corners of the room, even the ones that don't show the space you are asking about. I see it all the time. I am scared to ever post a question about how to arrange my furniture. 

Regarding that particular space, you can go with floor, wall-hung or a combination. So I will ask you to get out the things you want to store and display, sort them into "display" and "hide", and provide the dimensions of the items in those two groups. A picture of the two groups would help us. I'm guessing the process of sorting the items you want to store here will tell you what kind(s) of storage you need, and the dimensions, and you won't need us anymore. 

Oh, and don't paint anything until you get your furniture arranged. Paint is always the last thing.