Sorry for the double post!

We used large format porcelain tile that was light like yours, and it didn't come with bullnose. Instead of mitering or using Schluter strips, our experienced installer suggested a polished edge. He just used a succession on fine grit wheels mounted on a grinder for all the exposed edges before they were installed. It's incredibly smooth, and blends right in with the grout color we chose. We like it better than the appearance and contrast of adding something like a Schluter strip. If you have a dark surface finish on your tile and the tile body is light, a polished edge might not be the way to go, but what we did worked fine for us.

ACM - treasure trove of new ideas. Binging on placement of grab bars and grab bars with double lives now! Many thanks for pointing me in the right direction. Also I have decided on a white subway tile for the shower walls with the handmade whooshy look to the texture. Finally to the silly question that isn’t silly at all - the room in the bottom right of the floor plan which is cut off - we planned it as a bedroom with a wall of reach in closets + a spread of wall between two windows big enough for a queen bed. For now, though, we will use it as a flex room = office den and guest room. We’ll have a built In desk situation in lieu of the closet, a pull out or at least very large couch in lieu of a bed, and a media spot for den life. So A less mobile guest could stay at our house a little more easily as a result of this planning. Not ADA but something. On our urban lot size around here, you would often find the equivalent of this space used for a formal (no doors) living room or an office too small to accommodate a closet or a substantial bed so these trades are significant nods to thinking ahead. Since I added a good 3-4 feet to the typical size of this front room, finding another 5 feet for an en suite bathroom would really push the boundaries of the available configurations. So nothing is perfect but I will have more rather than fewer options if and when the time comes. I’ve heard others complain of the lack of this type of first floor options in typical configurations around here so these small considerations may set us apart for future buyers as well. Thank you all!

It happened to me with a mud bed shower, like yours, except my tile guy waterproofed the whole surface of the mudbed with hydroban (a sort of rubber paint on layer) all the way to the drain. Water got trapped between the tile on top of the hydroban waterproofing layer and would never dry out, like yours, and it spread gradually up from the drain. If he had left a 1/4 inch space at the drain, water would have had a chance to escape. The drain weep holes were open. The thread describing it is here: https://www.johnbridge.com/vbulletin/showthread.php?t=129219&goto=newpost%3Cbr A mudbed without the additional painted on waterproofing would allow the tile to dry out between uses, but your marble would look wet every day. Many people are OK with that. I would have been OK with that. And there a dozens of ways to do marble improperly at this same website (incorrect preslope is also common). Many hours of reading about it here. We had to rip out the floor and start over. I was able to save the wall tiles with careful demo, new flood test for liner integrity. Its really bad luck.