I prefer contrast with cabinets and walls so I would not paint walls the exact same color as the cabinets. If you really want to coordinate, pick a color on the same strip of colors, either Crushed Ice or On the Rocks.

I like the accent tile between the range and the hood, but I think yours is set too high. I would bring it down a row.

I vote for continuing the brick pattern and keeping it simple. Agree, you should lower it, if you keep it. Love your kitchen!