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.

I don't know how hot it gets in Auckland in summer (I've only ever been to NZ in winter!) but if it gets hot, then go for a pale colour. Dark roofs should be kept for cold places!

I read an interesting comment somewhere, where a lady invited a group of her friends over to lovingly point out all the problems they saw (through fresh eyes) with her home on preparation for sale. She said she was surprised at marks and damage that she had lived with for so long she no longer noticed them. We "owner built" a home previously, and when we came to sell 7 years later, we painted the garage and did those jobs that we had put off, and it became sad to finally see her at her best, at the end, when we could have been living in a completely finished home all that time. I read about a lady who decluttered her home, had it professionally cleaned (build clean, or bond clean) and had a professional styler do her home and she realised just how nice it could be and decided not to sell. :) ta

The setting is quite tropical, so a darker scheme with white trims has such a tropical holiday feel. You may consider using a concrete face brick for the lower section. This will be modern, and eliminate the need for painting, while still creating contrast with the upper level. Try a colour for the main house like Resene Evolution, or Quarter Evolution, both would be perfect for your style of home. The colour scheme that we recommend for you is our Rainforest Board which includes everything you need to bring the look together! https://www.bodoboards.com.au/collections/paint-concept/products/rainforest-paint-concept We would love to see updates as you go.. its going to be great!