Personally if I was spending an arm and a leg on the hex marble tiles I would want them to be the hero! I would keep the rest of the bathroom fairly simple. A standard large format white tile on the remaining walls would be perfect for both the budget and will allow the marble to stand out. I would do a grey floor tile, light or dark, what ever your preference. I have seen some beautiful bathrooms in those tones. The teak vanity will bring a nice warmth to the room.

if the budget allows for it, porcelain tiles are my recommendation. They look better, have smaller grout lines, can get them to look like any modern stone, like marble, granite, travertine or even available in wood look slats. My hot tip is the less grout the better, which means the smaller the tile the more grout lines, stay away from mosaic on the floor, I've seen too often these being ripped out because the grout dates and ages from soap scum etc. After seeing grey, black and various colours on floors, I would always go with white on the floor, easy to keep clean and no fading of the tile profile. Good Luck!!

siriuskey, Yes, the courtyard is open to the sky (no roof over it), I assume this is what you mean by double story. Ref. below photos, I would love to get this look, especially the first and last photo, where you can see family living space from the first floor. I can't achieve this in my plan as it eats a lot of floor space upstairs. The referred plan (photos) has a very big void combining staircase, hallway and dining area. I know it is not easy with cooling and heating when you have such a big void. So, I explored a few ideas (with my limited knowledge on this topic) before achieving the current floorplan. I have also thought about, in my current plan, extending the void on the staircase to the dining area (it is more like L shape) but i wasn't sure if that makes any difference. keen to hear your thoughts.

depending on the length of the shower...1500 or less have the linear waste across the opening at E and 1800 or more i would prefer a longer C but you should discuss with the plumber and tiler as various options means the floor has to slope in different directions..i notice that you have a small floor waste in front of the vanity...given the choice i would prefer to have all the floor slope toward a walk in shower with drain at C and no screen but if you want a screen to the floor that will interrupt the slope and trap water so it may be better to slope the vanity area and the shower space separately