Its really a great fireplace. I'd just get a more natural looking mantel piece.

Yes, I would add bookshelves white to keep them lighter and air. I agree, replace the mantle with a reclaimed piece.

I would take TV down, it is too high. Get a mantle that wraps around and some crown molding

I would remove mantle altogether and slurry brick

Yes, a timber mantel! Or reface entirely with natural stone.

Paint it white and add a big beam across like the others said!

We do specialize in custom cabinets, so my mind always goes to doing built-in cabinets on either side and a mantle spanning between. Something like this would be really nice.

I would reface the brick with stone it will make a world of difference. Go to a discount yard and see what they have that are liquidating but make sure it is natural stone

It looks nice that way if you want a really neutral palette. The green pops the fireplace. If you want it to blend in go neutral and add color pops elsewhere.