Floor plans of a single-family house with a granny flat, please tips and feedback

And what don't you like about it? Many things are better there than in your floor plan.

But you only come around with the info in dribs and drabs.

First, you didn’t fill out the questionnaire and now you say there were already proper plans. It’s no fun trying to think along like that.

When you said, "it should also work structurally," it already made my toenails curl and I knew the thread was only to be enjoyed with popcorn.

You’ve now heard from many that the plans are no good. Do yourself a favor and detach yourself from your own plans again; they won’t get better with fine-tuning. A new concept is needed, with a reality check and not one where every eventuality is taken into account (by the way, that was also my initial mistake with equally little buildable area).

What is wrong with the plans? What don't you like about them?

A completely different thought. You are planning another child, so I assume you are still under 40, and another 40 years should pass until the anticipated, possible need for care (excluding tragic accidents or serious illnesses). No one knows how care will be organized by then.
You said the neighboring house belongs to the parents and they also have a granny flat, did I get that right?
By the time it is your turn, the inheritance will surely have occurred (not meant to be heartless) and depending on whether you still have siblings and what they want, you could then move into the parents' house and have all the possibilities there that you have to compromise on today with your new build.

... No one knows how care will be organized by then. You said the neighboring house belongs to your parents and they also have a granny flat, am I remembering that correctly? By the time it comes to you, the inheritance case will certainly have occurred (not meant to be heartless) and depending on whether you still have siblings and what they want, you could then move into the parental home and there you would have all the possibilities for which you now have to contort yourself with your new build.

That's exactly what went through my mind when reading!

So I quite like the draft posted now. What don’t you like about it?

You don’t have to do everything the way others like it, but your plan is actually just chaotic :-(
Why can’t you improve things based on the second plan?

And what do you not like about it?

The first thing that comes to mind for me is that there is no granny flat.