Pretty vanity! Lots of storage.
My thought is that I would lean towards one blue thing but not both vanity and floor. Don’t get me wrong, I love a fun floor! But your vanity will probably be your showstopper and I’d go with a more neutral colored floor and then bring blue in again with a runner rug.
I’ll need to visit that toilet thread too!
I like your choices and I miss CB’s renovation threads. I hope you’ll share pictures when you are finished!
Glad to hear CB is doing well! You are lucky she can assist with the design. 
I’m with abasket here re: making the vanity the showpiece of the room. That said, the step down counter would drive me nuts, so my personal preference would be a vanity with a flat top.
I too question the step down counter, but if you don’t put a lot on it, it could be fine, and it looks nice.
Just a thought/question - are you going to be disappointed you didn’t go for a new tub too, when everything else is shiny and new?
Agree with the others on blue vanity, neutral floor.
I’d also consult with your tiler about 24x48 tiles on the floor. Although I am a fan of the least amount of grout, I think but am not sure that those large tiles are hard to lay in a small space. Depends on your tilers expertise.
I’m doing 12x24 on the floor in my primary
Another comment on the 24x48 tiles…the website pics show the flooring in very large spaces - much larger than a bathroom. Maybe your bathroom is much larger than what we see but thing about how many tiles could actually fit there.
Smaller tiles with more grout provide better traction. Also, when the floor flexes due to house settling, larger tiles can crack because there is not enough grout to release that pressure. I’d go with smaller tiles and ask for epoxy grout! Not permeable and doesn’t need sealer.
We looked at lots of tile at Decor and More and I thought the Luxe was the nicest. Rather than keeping the overhead lights I’d consider a lighted mirror as long as you have other lighting in the bathroom. I love mine.
Another fan of lighted mirrors. Electric Mirror makes amazing ones. We don’t really need additional light fixtures by the mirrors in our bath. Two large EM mirrors provide ample light and are great for makeup application 
or Mr’s shaving.
Those tiles also come in 12x12, which is the size we’d get. The current tiles (which are in both bathrooms, the kitchen, and the foyer) are 13x13. The guest bathroom is small; 106x56". I thought that tile was pale enough to pick up the blue but not really look blue. I was looking for simple and inexpensive. But that isn’t finalized; just a quick perusal last night. A white based tile would also work; that same tile comes in fog and smoke.
Re the step down counter, it’s the guest bath so only decorative stuff is on the sides anyway. It’s only fully used when son visits and he can manage. If that style came with a flat top, I would do that. But I kind of like the visual interest.
The ceiling light is the only one that lights the shower, and only needed at night because there’s a window in the shower. I would like to replace it but it’s not a necessity. I do my makeup and wash up in the main bathroom, which has great lighting.
Would it be nice to have everything sparkling new? Yes, but we hadn’t really planned on a total redesign, just to replace the damaged/worn items. We’re currently looking at about $5000; no wish to double that. But once you get to discussing with CB, it tends to grow in scope.
Update that we made the call on the vanity and bought the Brescia one I listed above. As it turns out, we have under 21" between the wall and the door molding so can’t fit a standard 22". And I learned that 60" wide 18" deep single sink vanities are a rare creature. Since we don’t want to take the time and money for custom built, we went with this 18" one. Which I liked from the start. The last one left in blue just about anywhere! Just crossing fingers that it isn’t damaged.
I am pretty sure I do want a bidet toilet. But I learned that our commode has 11" between the wall and floor bolts, which means we need a 10" rough in instead of the 12". (I should put this in what I learned today.) So that narrowed by choices considerable but I found a nice Horow. Since I don’t want to spend $1800-2000 on a Toto. Also looks like we’ll have to install a new outlet close to the toilet.
And I found a ceiling light that I really like (once I realized I had to look for damp rated). Although we don’t need it often, it will shine more light over into the shower. I think it kind of looks like a wave. (The link should work.)
Love the light! 
I’ve seen people trimming the door trim to accommodate an extra half inch of vanity (how do I know that - 
). Glad you found the right one, and since it is a guest bathroom, the uneven top would be fine.
Yup, I’ve learned a lot about toilet rough ins when my husband accidentally broke our powder room toilet! Not a lot of choices for a 10”’rough in. Can you add a bidet seat instead of an integrated toilet? Hope adding an outlet is not a major project requiring drywall work (hate that!).
I found this model - not crazy over the push button flush or controls on the side, but otherwise it has the major features of interest. Our current toilet needs replacing anyway.
I’d replace with a Toto toilet. Many can be found for $450-700. I’d like a bidet, but don’t know if they are used much. I wish the integrated ones work well, but fortunately, you have an expert.
I miss her pictures of her work.
If I want a bidet, Toto goes way up in price. I asked AI if a woman my age with arthritis in the hands and fingers should get a bidet and it said, oh, God, yes. Well, not quite in those words…
Oops. This one doesn’t come in 10’
CB said it’s unlikely current toilet is 10” so I checked model and- oops - it is 12” rough in. Whew!
I just bought a basic toilet at a big box store and almost grabbed the 10" rough in instead of the 12". I had no idea 10" was so readily available. That was almost a big oops.
Quick question on backsplashes - we ordered this vanity (which actually is three pieces). It is going in a small bathroom and we plan a fairly neutral floor and white painted walls. I know it needs a backsplash on the 36" central section and have been advised also on the two 12" side cabinets, even though nothing should splash there. I’m hoping to find solid pieces with a bit of design rather than individual tiles, since I am tired of grout everywhere. I may have to settle for solid white :(. Or individual tiles, although I’ve yet to see one I like and I’ve seen a lot.
Would the central piece look odd just ending flush with edge of the section? Do I need to connect it, like with something overlapping from the upper section to the side sections? Or can I just have the three separate horizontal backsplashes?
Edit to add, I like this tile!