Schots have heritage style pencil tiles in black, dark green and burgundy https://www.schots.com.au/tiles-parquetry/ceramic-tiles.html#q=&idx=schots_production_default_products&p=0&hFR[categories.level0][0]=Tiles%20%26%20Parquetry%20%2F%2F%2F%20Ceramic%20Tiles%20%2F%2F%2F%20Bullnose%20%26%20Pencil%20Borders&nR[visibility_catalog][=][0]=1&is_v=1. Blue might be tricker to find.

To what extent do you plan to tile the walls? Floor to ceiling or just the wet areas (shower/bath section and vanity splash back?). I would personally find full walls in that tile over-powering eg. https://www.houzz.com.au/photos/regents-park-contemporary-bathroom-london-phvw-vp~31719695  I prefer a more restrained use like this where the floor tile is used on one wall to give the illusion of more depth with other walls simple and white https://www.houzz.com.au/photos/wet-room-shower-bathroom-hampshire-phvw-vp~23525132  (Not a professional of any kind but...) Looking at your layout, I would be inclined to go with the feature tile on the floor, the bath hob (sides and surround) and on the long wall running parallel with the bath. The other walls I would tile and/or paint white.

I don't know about the osmo, I have only looked at it on the net. If you are looking for the satin look, I can guarantee that is what you will achieve with three coats of the livos Kunos oil as I have used hundreds of litres of it. If you look at their web site it will answer all of your questions and don't hesitate to call them. I would also ask if they have a recommended floor sander in your area, as it is not your normal sand and apply. Keep the questions coming if you have any. There is nothing I enjoy more than knowing that out timber resources are being treated in the best possible manner. These shots are of my own jarrah floor that show the scratches from the couch and after 2 mins repair. If this had been a poly floor the only option would be to sand the entire house.

I think she may have been referring to what is called a "French Pattern" which looks like a random mixture of square and rectangle tiles, often in travertine. However while it looks random it is actually carefully planned, and the tiles are made to a consistent thickness. It also depends on the type of tile that you are using. Many traditionally hand-made ceramic tiles have a natural variation, which adds to their appeal and visual interest. Other types of tiles, such as your porcelains are much squarer, flatter and almost identical. I would suggest that you go with your your choice of grid pattern, as laying a random pattern has too many risks (plus your tiler will hate you and charge lots extra). Be very careful about the selection of your tiles depending on your preference for a rustic more organic look, or a hard-edged architectural look. Make sure that the surface that you are tiling to has been properly prepared and is flat, smooth and true, as your tiler will not be able to correct imperfections if you have a bad wall. Best of luck, Dr Retro of Dr Retro House Calls