Hi, I'm concerned about the fireplace...I'm hoping it is a gas insert, not wood burning. Even so, most building codes or manufacturers of gas inserts require specific clearances from the firebox to combustible surfaces. We typically plan for non-combustible material for a minimum of 12" on each side of the fire box, 16" above (from box to mantle) and a hearth 18" in front and 24" wider than the fire box. Please refrain from lighting a fire in your fireplace until you verify that this new mantle won't go up in smoke.

Our fireplace is wood and gas however we never use it.

I think painting the bricks white would complete that section. It would also make it feel like it was part of the original plan for that space.

If and when you sell your home, please be sure to note that to the buyer. The building codes I referred to are generated to increase public safety.

Tear out that fire hazard. Unless you want your home insurance cancelled.