Architectural design / renovation of a single-family house - Your opinion is requested

I actually just wanted to know if anyone else has ideas for the upper floor, since we can change quite a lot there due to drywall construction.

Then go ahead and post the unchanged original floor plan of the upper floor. And write a few words specifically about what and why to change there. So far, the only thing that stands out to me is the toilet in the upper bathroom, partly located below the 2m line.

What is this supposed to represent:

? – I really can’t "make out" anything there, it looks like there are two roof windows...