I like river rock. I'd consider removing the paint -- sandblasting? -- and replace that mantle with something more standard. It and the river rock aren't friends. Looks like a pile of marshmallows.

Sometimes it is possible to make the fireplace appear more symmetrical as shown in the mockup below. We use a bifold fireplace door with black glass that you cannot see through when closed. The doors on the right would open to the fireplace and the ones on the left would have a black steel plate to cover the stone. Paint the inside of the fireplace black and it's not too bad when the doors are open, but you cannot tell the fireplace is off-center when closed. If you are intrigued by this concept, post these measurements and I'll do some calculations to see if it can work. Measure the width and height of the fireplace opening and then how much stone there is on the left and right sides of the opening. Don't measure the current door frame, but the actual fireplace opening itself.

I would sure like to know what is under all that paint and stuff. Could be some nice brick? If not then my thought is something right to the ceiling but no mantel.

IMO the TV is too high above the mantel . I agree the 2 boxes below the mantel make no sesnse since it appears this is a gas FP. IMO get a linear FP if that is the only place for the TV and then hang the TV at a much better viewing height That eliminatesthe 2 boxes and puts the TV in the right spot BTW the surround you show and the tile do not work together. It is also always good to see your style so post that in a comment here do not strat another post.