The black sofa could be considered a neutral, and therefore will go with just about anything. Do you like the white and gray, or are you looking for color? Bright colors? Subtle colors? Also with a baby I would surely want an area rug for her little knees. In this first picture you can see pops of red were added for color: [houzz=https://www.houzz.com/photos/2007-aso-decorators-showhouse-and-gardens-contemporary-living-room-atlanta-phvw-vp~26704] In the second picture, a monocrhomatic color scheme with a soft area rug: [houzz=] And in the third picture, yellow was added for interest: [houzz=]

You could put bookshelf over entry to where bed would go add tv on there, like in photo. Could you not get a pull out day bed for quests and then you have all the extra space, get book case on casters so you can move in front of bed when necessary

This is an akward compartamentalized plan. Can you move the east bedroom to the west wall opening up the living area? Add a kitchen penicila with bar and crockery.

Let your wooden beam be as it is. put your Led lights in the other direction ( two on each side in one rectangle , so the total will be 16 units of say 10 watt each Led.), as to balance the horizontal and vertical shape. Don't put anything on the wooden beam to retain its the beauty.