House bought before marriage and now divorce - what are the options?

I can only advise you to go to a lawyer who also knows all the necessary information and represents only you. Only one lawyer is skimped on in the wrong place. Who came up with the idea of just one lawyer?

I just wanted to find out here whether the option is possible in a divorce without a notary.

The divorce agreement does not have to be notarized. You can also make some changes in the land register without a notary.

I can only advise you to go to a lawyer who knows all the necessary information and represents only you. Only one lawyer is skimped on in the wrong place. Who came up with the idea of having only one lawyer?

From both! After the first conversation between us. I will think it over.

Yep. We fought over money almost to the death for nearly three years until the divorce.

For us, money or the house, just like the dog, etc., was always only the means; basically, it mostly comes down to hurts and also fears. Someone has to be extraordinarily disciplined and rational if they don't drift off now and then and "misuse" one of these issues (including children) in a certain way, even if, of course, everyone wants to push that far away from themselves. We are all only human and fail daily, especially regarding our own values, which I certainly do not want to condone.

But you also have to be able and above all want to separate that (unfortunately, there are many fathers who do not do that. In fact, many more than the "bad" mothers do).

I cannot confirm that for myself, but I believe you that there are sufficiently many such cases. I think that in such a case, each party pulls out the trump cards they master best, and the goal does not always have to be the house/money; it can also be preventing the other's happiness in life, revenge, or maintaining an image. I don't believe either gender is disadvantaged in this...

... and try to please everyone somehow.

Let me know when you’ve found this all-encompassing wonder, so I can be retroactively a bit annoyed. Make it "right" for yourself, and that is by no means selfish. As a nice saying goes: "If everyone takes care of themselves, then everyone is taken care of."

.... and now not let everything be "taken away" from me.

So far, it sounds more like you want to give it up voluntarily; your wife wouldn’t then be to blame for that.

I hear from many people that I might be approaching this too "nicely," but that’s just my personality.

That’s nice to hear about yourself, but is it always so? You—or rather, we all—also have your/our ideas, which I find completely healthy. You can be straightforward and clear and still be a nice person or even because of that, since that way you can also be a nice person permanently, even if your ex-wife might once be doing significantly better without you.

I want to solve it peacefully, fairly, but not naively.

That is a good intention, and it’s best to have someone competent from outside tell you what is also fair in the long term for both sides.

Regarding her new partner, I can only say that he has "not yet" moved in, but maybe some clauses could be included if that happens soon...

They’ll be happy to be observed by you or occasionally have a casual question asked to the children? Not for nothing, there are enough mediocre detectives who are supposed to prove that for their clients. That is exactly what I would never want, to have to watch my ex-wife’s life to gain clarity. That would be the mandatory part of my idea of fairness—that everyone can live their further life alone and in peace.
With our neighbors, the man regularly stands in the parking lot or sometimes walks around "his house," while the ex-wife plays Monopoly with the new boyfriend and the children. That makes me break out in a rash when I see it.
In my opinion, exactly such things also burden the children the most because they notice these subtle things very precisely and do not know how to deal with them.

Some changes in the land register can also be made without a notary.

Yes, have the last name corrected after the divorce. But that’s about it (except for insignificant exceptions).

Thank you for your reply! I don’t quite understand the comparison with your neighbor? I am the last person to spy on someone. I am overjoyed that she now has a new partner and hope for her that it lasts forever. It was very uncomfortable for me to have to tell that I have a new girlfriend (it was different with her before). I was really afraid of her reaction. When she told me six months ago that she has someone new, it was a relief for me.

And no, I don’t want to give everything up voluntarily, but fairly and without costs and much dispute. That’s all I want!