I was taught to always have the cut tiles at the bottom.

Running the floor tile up the bath would give the impression that the room has greater depth than it has. Running the wall tile down the bath to the floor would on the other hand make the walls feel taller. It really depends on the proportions of the space as to which might work better. Your tiler should be able to layout a few tiles so you can stand back and get an idea of how each option would look. [https://www.houzz.com.au/photos/maleela-contemporary-bathroom-melbourne-phvw-vp~11701292[(https://www.houzz.com.au/photos/maleela-contemporary-bathroom-melbourne-phvw-vp~11701292) [https://www.houzz.com.au/photos/north-carlton-renovation-transitional-bathroom-melbourne-phvw-vp~38027793[(https://www.houzz.com.au/photos/north-carlton-renovation-transitional-bathroom-melbourne-phvw-vp~38027793) https://www.houzz.com.au/photos/california-cool-in-the-castro-bathroom-contemporary-bathroom-san-francisco-phvw-vp~40145

yes to all, we did have the tiles professionally sealed, but sealing is not a cure all in my experience but I'm sure it helps considerable . my wife does buy those hand made goats milk styles soaps etc and I don't imagine there is anything more testing for stone, and yes it does mark. The Grey ( bane of my existence )granite much more so than the beige travertine ) I must admit though, the kids bathroom was almost non existent as one has sensitive skin and uses pump pack. I would also imagine climate, airing/ sunlight, volume of use and the time you have to manage it would also be contributing factors. We are way short on time and they don't get the attention they deserve, so I would suggest asking around, others may manage it better and it not be an issue. If your only doing your bathroom you may consider the risk factor not worth it for the volume, but for me, the advantage of travertine in the rest of the house far out weighs any marking issue in the showers, and wont stop me from using it again. To be honest when we sold the last house I just took to the shower with one of those paint scrapers with the razor in the end and most of it came off and it didn't detract from the look of the house. Sorry i have probably only muddied the waters even more, good luck with it.

Have you already sourced your tiles? I would expect most tile stores could help you find the edging tiles which I think are typically termed 'pencil' tiles for the style you have shown. We used bevelled subway tiles in our DIY ensuite. In hindsight we would have aimed to finish the brick pattern with 1/3 and 2/3 sized tiles (like in your pic 1) rather than full and 1/2 (pic2 and 3) to give a more even edge thickness/profile... Might not suit and we didn't use capping tile (I lost that arguement!) so it is probably more obvious in our bathroom, but just something you might like to consider.