Here is a moodboard i made of my choices. I just have a feeling the carrara counter is going to be darker grey than Id hoped

I would wait until you see the countertop. I love the penny tile you picked!

Wish I could upload a photo. We did a Q Quartz Calcutta vanity top, Happy Floors Apollo floor tiles, and a carerra hexagon tile for the master shower floor. Looks AMAZING.

You're mixing warm and cool tones, it could work if the counter top on the vanity ends up looking lighter( whiter) than gray. Can you hold off on the rest of the materials until you can see your actual vanity? That could help.

Beautiful choices. I agree – you need to wait until you can bring samples into the room, but my gut, and clearly your gut, says no. I will add to my gut with some personal experience: I used Carrera countertop, large hex on the bathroom floor, small hex on the shower floor, and subway on the shower walls. It is beautiful. However, I do not think I would do it all over again, knowing what I know now two years later. It is extremely hard to keep shower grout clean with marble. You cannot use traditional cleaning products and I have a regular battle with pink and black moldy grout. I had a professional cleaning company come in recently who beautifully steam cleaned it all. Weeks later, the battle is back on! There are a lot of great tiles out there, as well as great faux Carrera. I really recommend you look into it.