This old thread got revisited. @dani_m08 to answer the question about extra probe, I believe I ordered an extra one when I bought the set up. The probe wire is just setting in the junction box I think but honestly I cant remember. When I laid out the underfloor heating and the probe, I just ran another probe near the first probe, and it was then sealed into the floor self leveling compound as per instructions. then the end was just threaded into the wall like the one that would be live, and not connected, but just laying there in the box. Regarding the tile layout. I just decided to run it this way, after getting instructions on the 90Degree way, IIRC. The herringbone that I love is from my childhood and the side walks in my neighborhood that all ran at 45Degree. so that to me is herringbone. I know you posted on @sochi thread about her amazing bathroom and a wall mounted faucet. I would totally do it if I had the right sink for it. In my case I had made my sink out of soapstone and an integrated backsplash. The pictures of this bathroom reveal are no longer available because of the use of photo bucket, when it was Gardenweb. I did not keep my account with photo bucket. I'll add some of the reveal pictures so you can see the sink and floor. Regarding the sink there is no ledge for water to drip from my hands when using the faucet. The water drips right into the sink. In my other bathroom with a deck mounted faucet I am always wiping up drips and it is a nuisance. I much prefer the setup for this sink. Below: I love the flush finish from the faucet to the bottom of the sink. nothing drips on a counter or edge of a sink. Below: looking in from the doorway. Below: Here I am finishing up the sink. the backsplash was epoxied on as a separate piece. The whole soapstone install in the room took next to nothing to buy as they were all small pieces that I epoxied together with a 3 part stone epoxy. Below: this is the counter at the tub, and is in 2 long pieces but I was able to epoxy them together at there edges to make a wide slab for the top. All the soapstone was finished with a 60 grit sandpaper to be rough and this lovely soft tone of blue/green/gray/white. I did not oil it so this color tone would remain light. Below: If I recall correctly @sochi helped me decide on this Hubberton Forge Mirror. I have 3 different metals in this room, but they are all a cool silver to black color. Below: the center of this tower shares space with the kitchen on the other side of the wall. there is also some extra space that houses some electrical wiring. this is an old simple house. this bathroom was an add on when it got move to the farm in the 30s IIRC. The plumbing was all rearrange and some of the details that were orignially there I kept but updated it, such as this tower feature. The old one went and the carpenter did a wonderful job with this one. Below: This feature was another thing I kept from the old bathroom but flipped it from the other end and had the carpenter put drawers in it. Before it was a hell hole. things got lost and the build was soooo old and creapy I didn't like using it for storage. Now it is perfect for storage.

I can't tell how true the colors in the photos are -- they look pretty dark. I'd look for a medium gray (warm, not cold) or tan tile that matches a tone in the slate -- there are a zillion cement-look tiles that might do the trick, say -- and use that on the floor and around your tub. You haven't said what color your vanity is, so it's hard to suggest a counter, but again, you might look for a stone that coordinates with tones from your slate while giving sufficient contrast with the vanity (that is, a mix of grays and browns with a cream or white vanity, maybe more toward cream with a darker wood vanity)... Should be possible to make it all look intentional. Maybe you can find a small slate accent tile to put at the top of your tiling near the tub to help tie things together (or maybe as a backsplash for the vanity, depending). Here are a smattering of photos that might help you think:

IMO the floors should be the same and your inspiration pic has a very simple stacked wall tile with that floor and that is what I would have done in your shower too I think the 2 patterns will compete with eachother and the dark grout on the walls will make it even more so

That is a beautiful vanity! But it's kind of distracting since it contrasts so much with the shower. I don't think painting will do much to fix the two different busy materials. I would look to get a new top for the vanity, a subtle light solid color, maybe a creamy white that ties to the shower area. Then you might consider painting the room a more subtle white that is warmer like the shower area. The current white looks rather stark next to shower.