You can put the TV over the fireplace, not the best situation but the way the room lays out it is the only logical place to put it. If you could you should add one additional layer on your mantel that could extend it out another 4" to deflect the radiant coming from the fireplace. I would also mount it on a slimline mounting bracket and have the bottom of the TV no further than 4" above the mantle. Ideally you want the TV to be in as straight a line as possible with your eyes. You don't want to look up too high at the TV, it's like being at a sports bar. Also if you can snake up the power and the HDMI from the cable there is a box they make that has both in one so it makes for a very clean installation.

Considering my house is upstairs, my home would be useless for when I'm old. Absolutely useless. There's no shower downstairs either so I'd have to install one of those elevators that help you go up the stairs.

Hope post shows, got some weird error message

I'd love your advice - Where would be the best placement of my appliances, sink, oven etc? I would love to have my sink under the window - do you think it could work?