Thanks :) Yeah decided to go with tile. So sand cement is ok over existing tiles if I prep them first? Only problem is, the new pad can only be about 30mm at it's thickest (leaving up to 15mm for tiles) otherwise it'll end up being higher than the hallway floor. So I either need to make the fall shallower or not bother with the waste and make it all level. If I made it level, could I use levelling compound at that thickness or would deck mud/sand cement be the best option? Also, should I be putting in mesh for strength? (I know I should (and will) ask the local hardware what they suggest, but it's great to have suggestions from the Houzz community also)

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 have bare walls, then choose colours that won't clash and would tie in wiht the room. Then pick out colours you actually like and pick a favourite. Most everything will go with Grey but contrast is usually more visually pleasing.

I think your layout is generally good. With a one bedroom it's nice for guests to have access to the ensuite without having to walk through the bedroom. One thing I do notice though is that there is a lot of hallway/storage/circulation space in the center of the building (in the two bedroom portion) that might be better used as living space. You could pretty easily make the ensuite in the one bedroom larger for example. The wash house space seems unnecessarily large to me as well. You could push the wall dividing kitchen from wash house almost all the way back to where the toilet door is in this plan (you'd then have the toilet door open into the wash room to the right from this viewpoint rather than straight ahead). This would leave much more kitchen to porch access, which would be nice.