Never thought about going though the shower to get to the toilet, but if you can keep the door dry and protected, it should work. When I build my walk in showers without a door or a lip, I put the showerhead on the wall where the sink is so the water sprays away from the door. This way the water doesn't leave the shower are and make a mess.
I try real hard not to have a window in the shower. Lots of homes have them above the bathtub that is also a shower, and it's the first place problems start. You have to really work hard to get a good seal, and even then, windows are designed to keep water out from the outside, not from the inside. Glass bloc works, but it's outdated and not something I'd put into a new house. Kind of a 90's thing. Natural light is a nice thing, but for a small area, you don't need a lot of lighting to light it up. I'd put a shower rated can light in the ceiling of the shower instead of the window. Most of the time, it's dark outside when you are in there anyway.
The door to the closet should swing in.
Eddie