Just a little ceramic information to share as a potter. Vitrified simply means the clay has become glass like by being fired to its proper maturing temperature. Usually ceramic tile means it is a lower temperature clay like earthenware or terra cotta. Porcelain is fired to the highest temperature and is more vitrified if you will. This usually means it is less porous to to absorb water and harder. Low fired ceramics with glazes much darker or lighter than the clay body will show chips easier. Rectified has to do with making the edges precise enough to fit smoothly together for less grout lines. So porcelain cost more to produce but it is more sturdy. All clay tiles should be vitrified.

Leave the vanity in the ,space needed in a walkin is personal but in a 8 x 8 if you put storage on 3 sides you will have quite a lot of space, figure out what you have now and see if it will all fit or will you need dressers in the MBR

I am assuming you haven't finalised your wall colours and colours of any other fixed elements. In case you have finalised your color scheme you would need to see which of these colours blend well or complement with that scheme. Assuming none of this info is available, then you could look at the neutrals which go with all colours. The white tile and the 2 colours at the end would be preferable. If you want color on the floor as well as drama, you can choose from the 2nd options from both sides or even the 1st from left.

normally tiles are not all geometrically perfect. the edges are often chipped or curving. that's the reason most designers use spacers and grout. but the margin of error is 1 to 2 mm. anything more than that and you can ask for a replacement.