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.

See the edging around the top of the tile in the shower? Can I do that to an acrylic wall panel? (I hope this picture works?) Eclectic Bathroom by Chestnut Hill Interior Designers & Decorators MANDARINA STUDIO interior design

I recently saw this episode of Ask This Old House where they demonstrated painting tiles - especially as a solution to get one through till an entire redo is possible. http://www.thisoldhouse.com/toh/tv/ask-toh/video/0,,20902001,00.html Looks like you are doing a great job!

those tiles from the 1800s are encaustic... the color goes all the way through. ceramic tiles are red in the middle and have just a relatively thin layer of color and glaze. porcelain tiles do have a color matched center (look at the edges to tell) but i'm not certain that all of the pattern goes through. at least it would wear off and turn the main color, not red.