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.

First of all, you should change the door swing from Left hand to Right hand, so you walk into a room not the wall. Put the bed where the dresser is now and the dresser on the other wall. Other then that there is not much room to do anything, or replace the window, insulate a wall and leave everything as is. Good luck

Get the professional sander guys in to repair the living areas and kitchen but don't go too dark with the stain as it will kill the lovely grain in the matai. I'm thinking a couple of tones richer than the timber knots showing in your photo, definitely no yellow tone at all. In NZ stepping on to carpet especially in a kiwi winter is so much nicer than a cold floor board shock!!! A nice area rug for the lounge and you're done.

If you think hitting the lamps could be an issue, just move them a bit and add some low accessories (opposite sides to pic below). It's better to have a bit larger lamps and with your ceiling height anything shorter would look skimpy and they don't overwhelm the bedside tables once you balance with something above the bed. Just a thought...if you accessorize your bedding with some soft colors, they will also help to compliment the glass and crystal. You could even change the hardware to a silver.