You're right, everyone IS watching you. Just to be sure, this forum has a volunteer committee that takes note of where you live and sends a team to stand in your yard and look in all your windows. :) In reality, most likely none of your neighbors cares one whit what you do in your house. Normal people are busy with their own lives. Besides, during the daytime, if you keep your lights off inside and stay away from the window, it's almost impossible to see you from outside anyway. Stand halfway across the yard and try to look in a window, and you'll see what I mean. It's another story at night, of course. But there's no sunshine at night, so you don't need to open your window then.

That is a beautiful fireplace! I think that a dining set close to your kitchen would be more sensible. I would not put a tv above that fireplace, but maybe between the two windows or to the right of the fireplace. Then your seating should face both which would work in limited space. Is this a studio? Do you have a bedroom?

Can you return it and get a smaller one? (I admit I think your fireplace wall is lovely and I personally wouldn't ruin it with a television. But I am a tiny minority who has lived without television for almost 30 years.) Is there another room in which to put it, or do you prefer to use this room for watching it?

Here's a couple unique ideas. Running the shiplap right up to the opening may not be up to code as shown in the first option. Fortunately there is an aluminum shiplap that is non-combustible that is available for this purpose. So the solutions below can all be done with metal surfaces specifically designed for this type of application where there are heat restrictions. The reason your wood mantel is as high as it is, is most likely because you are required to have that clearance above the vents to the bottom of a wood mantel. The examples below have the mantel directly over the vents while still allowing airflow. A mantel will be important in order to block heat from the TV. I see no other way to do this than with a metal mantel. This is a metal mantel shelf. The center section beneath the mantel is directly over the brick vent and pops out a couple inches to allow air to flow around it from the vents. You would see the air space from the sides. This is a metal mantel surround with a metal facing using the same concept for the center piece under the mantel. If you need a resource for these materials let me know.