Window sill height 130 in the bedroom / study?

Then build however you think best. You do not seem satisfied with any answer and expect that from the hints at least one ready-to-print proposal will come, which you can implement exactly like that. But no one here can provide that.

There are also few examples of absolute symmetry in very good architecture.

I strongly disagree, there is a lot of excellent architecture that is both almost perfectly functional and also symmetrical. Hardly anyone can afford it...

I am not a fan of houses whose façade completely lacks any harmony because they were planned only from the inside out.

Building from the inside out and a pleasing window arrangement do not at all exclude each other. : If you can and want to change only little, that is fine. In addition to the suggestion "light from above," there are also excellent lights that come very close to daylight. Try searching for CoeLux in connection with room+project in a relevant search engine. Regarding bathroom windows – location is everything when it comes to view in and out. We have a terrace door in the bathroom; from outside a deer occasionally looks in. Facing neighbors or a street, I might do the same, but then with a curtain or another privacy option.

Regarding bathroom windows - location is everything when it comes to view and visibility.

But you have noticed that the non-exposed bathroom situation is exactly why the windows there have the high sill? And that at this corner of the house perhaps more focus should be placed on light for other rooms. As it is now, each room upstairs has its disadvantageous spot. It's like casting pearls before swine…

But you did notice that the non-exposed bathroom side has precisely the high windowsill for that reason, right?

I did. That's why the suggestion with light from above.

I have. Hence the suggestion with light from above.

For the bathroom? Or for what? Why counteract when you can simply switch the rooms? The design of the upper floor is not rocket science. These are four almost identical rooms. The main bathroom can be positioned very well with a short (heating) route via the utility room, etc.

Having a skylight in the bathroom is really a nice thing.