So, the floor definitely was the biggest PITA of the project, manly because it wasn't flat. I used leveling compound to do the rest, worked like a charm, but of course you have to come up with a way to seal the edges so it doesn't run into the walls etc.
The biggest flatness problem in the end were the fiberglass tape connections between the hardibacker boards. I sanded them flat all the way where I'd get into the tape but these were still not even with the rest of the floor. I had to pay good attention to not get any lippage around these areas.
Happy to report that after grout I was able to slide a 5 gallon bucket across the entire floor without it hanging up anywhere. The 1/16" grout helped.
In the image the floor has a lot of contrast. In real life it is a lot less pronounced, more like a marble. I wanted something that doesn't show dirt easily, and that certainly was accomplished. There were no floor board tiles with this tile set, so I went with wood. Next time I think I'll want to go with tile and will stay away from floors that don't come with floor board pieces.
So, after this I'm taking a couple months break and then dig into the master bedroom. I bought the same vanity and tiles to make it a match.
Thanks for all the great input everyone. And yes, the stack height was perfect to mate with the hallway laminate.
G