I don't know what "device rating" means. It looks like the only way you can fit your TV to the right there would be to fill in the open space, removing the framing, and then hang your TV just above the cupboard. Or hang it on the stair wall over a very slim console. Then one couch in front of the windows and one facing the fireplace. Put an end table where the couches meet, with a table lamp.

I wanted to type decorating and I don't know why it auto corrected to device rating...

About hanging TV on the stairs wall, it will be opposite to the wall with large windows and will have glare during the daytime. Can I remove the fireplace mantle, make it a stone accent wall and have tv over it. I am not planning on using the fireplace ever

" I wanted to type decorating and I don't know why it auto corrected to device rating... "

So edit it and fix the wordage.

" Can I remove the fireplace mantle, make it a stone accent wall and have tv over it. "

No, TV will still be too high for comfortable viewing. Get rid of the fireplace and the niche entirely and put it on that wall if you have no intent of ever using the fireplace.

Use blue tape to mark on the wall of the niche where a 65” TV would be positioned (assuming closing up the niche will be required). This is the best way to see what it would look like.

Also, mark on the floor with blue tape where your 2 sofas would fall with this type of arrangement. Posting a photo of your sofas will help us make rug recommendations which is where you would start with the decorating part.

I need wall measurements of that whole wall where the FP is . You need to provide that and the actual measurement of the TV not diangonal but width and height . Do you not have another space for TV and honestly recling furniture eats space and your space is not huge to begin with. A rug is the last thing to worry about .

Actually paint and accessories are the last thing to worry about. A rug is key to the start of ‘decorating’ which is one of the things this post is about.

A TV over the fireplace doesn't have to be "too high" if you use a "mantel mount".

Where do you want to place the TV?