You could hang drapes so the window looks centred (i.e. more panels on one side). Any photos?

I would allow for at least 36 inches if you cam and no less than 28

I agree with emily. if you want leave connections and/or a little extra room for what you don't want, but feel you may need for resale. I think the tub is a pretty important item. wet room not at all, and shower is give or take. i would prefer a big shower and a tub for soaking in, but I have always had the combo. I remember my mom built during big wet bar craze, she did not care for one. had space built, capped off connections and use as a closet. Now it is 35 years later, everyone wants to buy and tear down. Darned if you do, darned if you don't. i agree, I would also really like the separate toilet, we are not share everything people.

Have you tried hitting up the place where you bought it from or had a look at the manufacturer's website?