Hallo mr.! im nartchitect, i have 2 option design for you, I’ve read all your information and preference that you give and all the question on your wall too. form what i've read you like a simple design and easy to clean, light brown colour, prefer shower than bathub with a lot natural light.
i dont upload all the image view for the detail you can see on my concept design i hope that can satisfy your expectations.