I'd paint fireplace brick first.

Also consider removing the wallpaper and update the light fixture.

I would not add wide moulding in fact I would remove what you have and keep the walls plain as it looks like your ceiling is a little low.I would paint the brick and then paint the walls a very light shade too. The room in this picture has a very low ceiling and no windows and we found that most people who visited didn't even realize there were no windows. With no natural light you really need to have lots of artificial light not just a center light fixture.Also the pictures on the wall could use a little organizing to look a little more attractive.