Desire for joint property - currently separated

I didn’t understand it that way either. But I think it’s good that you are addressing it NOW and thus it will be clearly and fairly regulated for both from the start, whatever you decide to arrange.

Well, the chosen approach here (and it’s already out there) is about negotiation and therefore about positions – of two people. It has nothing to do with fairness at all. Those who like this kind of balancing in a relationship, go ahead.
Given the woman’s income and capital, having fear of “nothing” is, in my opinion, a bit too little trust. There is a joint child involved (which already determines the decisive leverage anyway). Does the child then have to pay rent as well? And does the father pay maintenance to the mother so she can transfer the rent to the landlord for herself and the child? Or does that come from the child benefit? And if you monetize here, which is no problem for virtual appreciation of houses: What does the father pay in general for the upbringing of an heir, or is that free-for-all? Maybe a comparable price for surrogacy from Ukraine multiplied by factor X for Germany? Then the calculation probably looks completely different. Who bore the realized income losses during parental leave, and who the reduced career opportunities in the future?
All positions one can take; depending on one’s personal value system, absurd or completely legitimate...

All positions that one can take; depending on personal values either absurd or completely legitimate..

That's how it is, and everyone is free to do so, including the OP, without anyone assuming negative motives. There are countless examples living this out in different ways, and I would be cautious about putting someone in a corner just because they are looking for a solution for themselves and their partner that feels right for both or all involved. I don't quite understand why fairness should be out of place here; I thought that was a prerequisite for getting along. Maybe some simply don't ask at all or just assert themselves, or the lady/man simply doesn't object... that's possible too. Or is everyone around us always eternally happy? I find it absolutely appropriate to think about such things and am surprised by the oh-so-moral component that is often wielded, which, of course, one claims primarily for oneself. Your extreme example can of course be carried on to perversion, I believe you on that, just as I can give you examples where perversion occurred because people let themselves be guided by the moral cannon instead of resolving things factually beforehand. No one wants to disadvantage anyone here, but if the woman insists on 200TE, why shouldn't the man be allowed to have a different opinion without feeling like a morally bankrupt father? I don't understand that... and the remark about the child goes both ways, and I wouldn't know what to reproach the father for here. I don't like the condemnation just because someone does it - more or less successfully - differently themselves or maybe had to.

As long as no one feels hurt in the discussion, anything can be discussed and financial matters can be exchanged transparently. On the other hand, I am not a fan of "yours is mine & vice versa" in fundamental financial aspects. That does not mean that the partner will sleep under the bridge if he/she has no money. I have no desire for my partner to a) become financially stupid due to no plan & b) knowingly be financially dependent on me or vice versa. I find that extremely unattractive.

We even have both: a joint account for shared expenses like rent, etc., and separate accounts for the rest. The exact cents are not calculated, but I don't find it objectionable to pay attention to both partners contributing equally financially. The situation of the OP is not simple, and I can't quickly think of how I would solve it either. My feeling is that the OP restricts himself financially to pay/improve the house, while the wife does not contribute anything to that at first. It feels unfair if she treats herself from the saved rent money. He might benefit from the increased value, but as long as the house is not sold, he actually gains nothing from it. With a child, it all becomes much more complicated because usually there are also salary losses involved. The man would then have to compensate the woman, or both work less. So many aspects come into play, and it will probably be difficult to find a fair distribution.

It does not exclude each other. As soon as "something" is there, you start to think. It’s easier if nothing is there....- . No, I don’t think it’s overly ingrained, only many don’t think aloud about it or like to talk about it openly. But these thoughts do take place anyway.

Yeah, sure, and then every cent is recorded and calculated.

Yes, of course, and then every cent is recorded and calculated.

The one who wants to.......or likes to exaggerate-