That was me who mentioned 18 x 18, enduring. The reason I like large format square tile is it doesn't have a direction to lead the eye like rectangular tile and is very calming and serene. More spa-like imo. Dyhgarden laid her rectangular tiles with squares and it eliminates the directional pattern. This is also a nice way to lay 12 x 24 in a bathroom. Rectangles and fish scales in the shower are two tile shapes. It really depends on how plain the vanity area will be whether you want to introduce a third strong geometric pattern with the floor. It's hard to make recommendations when we only know what is planned for the shower area.

Simply White has a yellow tone. The tile has an orange tone. If you stick with colors with tones of yellow to orange, no matter how light or gray they are, they will work. 903 Pirates Cove Peach is a near match to the tile. I split the difference in tones between the tile and Simply White, then increased the saturation to get both 176 Goldtone and AF-305 Ylang Ylang from Benjamin Moore. Below is a photo showing all these colors on your wall. I cannot say that my color rendition is exact, nor can I say that your monitor will produce these colors the same way mine does. However, I found the color names for those I produced via an online program called Easy RGB.

I like these pendants. even just with doing the picture, it makes a diff! these are prob at least 14" in diameter. you wouldn't want to go much bigger. the weathered bronze color on the rim goes well w/your cabinets. I gave your the sconces over the shelving. it's prob too late, but I do like them. except I wouldn't do black,I'd do the white w/nickel base. as for the lights elsewhere, they don't have to be expensive. The entryway light is fine. just upgrade your bulbs. if you go to an actual lighting store, they have a ton of bulbs you can choose from. get the LEDs since you can do more wattage for better lighting. (and they don't make the room hot). this is a pic of the kitchen w/those pendants (from Savoy House. seeded glass). https://www.houzz.com/products/pendant-lighting/manufacturer--savoyhouselighting1/p/36?oq= so you can see the other light they used https://www.homebunch.com/new-home-plan-ideas/ here's the entire house^ Savoy House is here on houzz. here is another one of theirs:

When there are several different natural lights coming into the room, I go with the one which delivers the most light…so, guessing the light from the slider is the dominate light (West). Try B.M. I know you really want a white for the walls, but with all the different light neutrals you have in the tile and the cabinets, give a moment’s thought to White Winged Dove, as it has a LVR of 76 (meaning not a whole lot of undertone) I think you need to consider your floor tone more.