Wow, just wow! This looks amazing, well done.

I think you have to make a decision about what is possible. On the plan you can’t make this shower room a Jack and Jill arrangements because of the different levels. If you make the larger room into an ensuite bedroom this disadvantages the smaller bedroom that will have to use facilities on another floor- I would only do this if:- the smallest room is bedroom 6 and is therefore more likely to be used as a study. Alternatively the small bedroom may be bed 4/5 in which case I wouldn’t make occupants use a bathroom on a different floor unless that bathroom is underused (by which I mean there is only one bedroom using the facilities on the floor below)

I like your plan 1. Or perhaps your bedroom 4 door could be angled so it goes across to the corner of where your shower is situated. Like Sarah L mentioned, need to consider how you get furniture in/out

Re C: Sorry to throw another idea your way, but there is another way to set out the storage in C. Rather than have the cupboards/wardrobes opposite the bed, you could dedicate the space under the sloping roof to the cupboard/wardrobe. ie there would be a long row of storage running parallel to the bed. (I've had this in one of my houses). To look at the wardrobe doors look square. The pitched room is hidden behind. The advantage is that you can then have sliding doors on the wardrobe, and a long hanging rail. It's only a half height -- so not good for dresses, full length coats - but fine for shirts, skirts, suits etc. This leaves the wall opposite the bed (in orientation C) free for drawers (maybe two sets of drawers - if two people are using the room) and you can display photos/vases/ etc attractively on the surface of the drawers. Maybe put art work/photos above the drawers (which you can look at from the bed), or wall paper the entire wall. So - you get a long row of hanging space (behind neat sliding drawers), you can store stuff behind and below your hanging space (because the eaves go back further), you have plenty of space for proper drawers, and you look at an attractive wall when you walk into the room. (Disadvantage - not much full height hanging space - you could add some but not alot behind the door)