I'm not in favor of painting wood or brick. once you paint anything you are committed. I love built-ins too, a perfect place to share your family and travel treasures or collections. the bones are already there you bring in modern elements with furniture, color and your own personality. a good cleaning and staining if you don't like the color keeps its character. I agree you should take out the faux beams, they seem to bring the ceiling lower. removing the shutters will bring light into the room. a warm color (golds/greige?) for the walls will compliment the wood. should be fun, enjoy!