Eventually when you come to resell, a pool is an added plus. But for your own purposes, emptying the pool and adding a deck over it with a hinged door and steps placed below would be great for storage (as per option b but bearing in mind you could revert). All the best for your lovely new home.

is it a curved staircase? What is the highest point of the staircase? maybe you can do something like this image:

the design looks great . According to me one side of windows can be used as bed wall . we can have blackout curtains or blackout window blinds . You can even play with drapery to define the area behind bed. We already have seating in the room so next we can do is give a console/ study table with an puffe / chair to it. also one can add a bench at the end of bed. Size you can check on your Autocad . Bed wall should be the focus when one enters the room, so I feel the bed should be placed like this . Dimensions of furniture and circulation space you can work on. Also WC should be on the washbasin side to avoid Future leakages and dampness in bedroom wall. all the best

I prefer shades of brown ..blends well with all colors.