What is the closed blue area between the closet (?) doors?

thought was a linen closet accessible from the bathroom and a place for storing shoes inside the walk-in closet

OK, so I'm nit exactly sure what the question/problem is. You have plenty of space there, that's for sure :)
Would you like ideas on how to include a tub? Or just other ideas in general?
I'm not sure you're utilizing the space best: for example, if your doors are to scale, the way you have the closet drawn is not going to be very useful (or at least, as useful as it could be given the amount of space you're working with!) with that built-in as drawn.
Are you able to add a window anyplace? The biggest thing that would improve the space, I think, is a window (even though you do have the window, which is great!)

Stacyneil, I'm hoping someone can help with the design. The doors are to scale (2 - 36" doors and 32" doors into the closet. We do have a small window over one of the sinks as drawn which can be removed. Unfortunately, there is not much of a view. We considered adding a window to balance out the look from the front of the house but every design we came up with has the window in the closet (or over a tub which we are not excited about.) To put things into perspective, this room is on the 2nd story above the garage.

Is there currently plumbing in place? Right now everything is spread out and you might need two soil lines / stacks to service it. I would not want the toilet backing up against the bedroom wall. In a space this size I would also want it in its own compartment and with more direct access from the bedroom, for the middle of the night. But first I would need to know where the plumbing currently is, or is planned--it makes financial sense to have an efficient plumbing layout even in a large bath.

In general I would not have the closets accessible only through the bathroom. You should also plan doors into walk in closets so that they open into a corner or open with enough space behind them for storage: 15" -18 for shelves, less for shoe shelves, 24" for hanging.

I would also not want the door to the bathroom centered on the foot of the bed. Are you planning on watching TV in bed? How much bedroom furniture? A seating area in the bedroom? All these things should be sorted out before you make the BR smaller. To put it in context, if you drew a line straight across the "top" shower wall to the other wall, that 5'6" x 9'7" used to be considered a generous size for a bath and you have roughly 4 x that for bath and closets.

Why not a window over the tub? Personally, I love that. I wish the window over our tub came down lower so I could see out of it while bathing :)

Also- I wish I had a window in my walk-in closet.

Windows in both those areas can add a lot of light and enjoyment to the spaces.

There are a lot of opportunities here. If I get some time later I will try drawing some options up for you.

thank you - all ideas are truly welcome!

Salmon:
The way you've got the bathroom drawn there's a lot of wasted space ("hallways" leading to sink and in front of shower). If you can reconfigure to have fewer "hallways" you can have a larger closet.

I'd try swapping the closet to the lower end of the room, which has a lot of stair steps and angles. Closets can better use up all that space than an assortment of bath fixtures.

If the closet wall is basically the toilet room wall all the way across to where you have the sink drawn, with a door in the middle to the closet, you could do this:
-put a sink on either side of the closet wall
-move the door to the bathroom up a tad
-put the toilet room, tub, and shower along the wall where the closet now is.