Attic floor room layout - We're running out of ideas...

The corner is the entrance, meaning the canopy. The dashed line shows the entire roof. Our son is 11 months old; he should get the largest children's room. The second children's room is intended as a sports room (treadmill, weight station).

I mean the dormer in bathroom 1.

Which roof pitch?
Does the dormer have to be?
Ceiling height + floor height on the ground floor and the upper floor?
How long is the staircase?

The roof pitch should be 38 degrees. The dormer is not necessarily required. The architect had planned it, but it was not a must.

2.80 m is the ceiling height on the ground floor, in the attic we can still adjust it a bit, depending on how high we plan a storage.

I do not know the exact length of the stairs. 4 sqm are marked, I cannot determine that exactly.