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.

Good that the heat/air system is over the door and doesn't interfere with your decor too much. It appears the ceiling fixture to the right of the FP might indicate that the dining space is there. Put a sofa in front of the FP and two small accent chairs with it, facing each other over a round glass coffee table. Can you wall mount the TV left of the FP? I think the room is too narrow to put the TV above the FP - you'll strain your neck. If you mount it opposite the FP, a sofa and two chairs could work but will need to be small scale - try apartment-sized seating. The sofa could face the window with the chairs opposite it. You could turn to see the fire or to watch TV. Swivel chairs come in handy in such tight space.

on the landscape plan - The road frontage is the left hand curved side & the black rectangle is the position of the outdoor fire.

You have "wear through" which is when the finish is pierced and the wood is exposed to the elements. The dark areas are where dirk/water/mud have stained the floor. It is possible to get this out... but probably not all the way. A floor that has wear through needs to be sanded right down, stained (if you wish) and then refinished. Patching can occur...but it is almost always a waste of time because the "look" can be very different from the original sitting right next to it. I don't recommend it for your situation. The second photo shows the deep scratching. Ideally, you would have had your floors looked after BEFORE wear-through occurs. There are some "regular" scratches to the Left in photo 2. You can see it is visible...but no discolouration....THAT is where you draw the line. The darker "wear through" to the Right in photo 2 = too late = full sand and refinish. If you catch it BEFORE wear-through, you can do a "buff and coat". This is a light sanding with a few coats of high end finish over top. The buff and coat is roughly half the price (in Canada at least) as a full sand/refinish. For this reason it is important to catch the floors before you get to this level of scratching.. That being said, you now get to pick some stains (test patch, test patch, test patch). The first photo shows two different woods...you could ask to see if the lighter would could be matched to the darker wood (lots of testing to achieve this). It won't be pefect...but then again you wouldn't have used reclaimed building materials if you were after "perfect". The match can lessen the colour variation to a more manageable (design wise) level. As for "good for dogs" - natural colour of wood = best colour for scratches. A lower gloss (like a satin) can help. You can ask for the "best" finish with scratch resistance that comes in a can. You will pay a premium for it...but it could/should save you thousands of dollars over the long run. A highend, scratch resistant finish means you can get away with the cheaper buff and coats (every 7-12 years...or so) and be able to retain the original (expensive) finish for the full 25 years. The other thing to note: dogs claws require trimming 2-4 PER MONTH when working with hardwoods. This is what the hardwood flooring refers to as "routine" trimming. Some of my clients thought "2-3 PER YEAR" was "routine". I laughed. You have heavy, high energy, powerful dogs. A single lab can cause some damage over time. Two labs can do a number on a floor. Three labs and you have a very short lived hardwood finish. You have 7. I would find the most expensive, scratch resistant finish available in Australia. I would have the maximum amount of finished put your floors (you will pay extra) it and I would budget for a "buff and coat" every 5-7 years.