The Tiling is Done. Caulked, too.
Will I ever, ever, EVER use chair rail again on a wall with an outside corner like this? Why no. No, I won't.
The wall doesn't meet at a 90 degree angle, you see, so my Tiling Toy doesn't work.
I destroyed 3 pieces of chair rail trying to get this aligned correctly, and finally settled for "good enough" rather than perfect.
Next up: towel bars, wall repair, and paint.