Construction progress: Duplex with WU basement and developed attic

Well, but I do find the thing with the car pretty bad. Worth €8000, but only got €3400 from the insurance. (The €11,000 is misleading, so I’m going to leave that out). I think I would have taken action against that too. Somehow it’s like a slot machine... you’ve already put in €3000 in the first step and didn’t win. So you immediately add another €1500. If that doesn’t work either, do you go to the next level?

Honestly, what you and some others here call a 'sense of justice' is obviously a pathological personality disorder.
It is ALWAYS someone else’s fault, it is ALWAYS your point of view that is right. House, car, job, the list can certainly be extended at will.
The fact that you constantly isolate yourself and put yourself under massive pressure and don’t reconsider even serious physical impairments speaks volumes.
I hope that this somehow ends well for you. The houses soon to be completed may seem like a victory to you, but unfortunately they are a Pyrrhic victory.
The real battle takes place within you.

Are you trying to tell me now that, for example, I am to blame that the left-turner ran into my car on a red light? Should I reconsider my position on this? I do not deny that the whole thing involves effort and sacrifices. But if I didn’t believe my position was right, I would hardly do this. However, I have always said that I would not recommend this path to anyone.

Well, but I do find the car issue really bad. Worth €8000, but only received €3400 from the insurance. (The €11,000 is misleading, I'll exclude that). I think I would have taken action against that too. Somehow it's like a slot machine... you've already put in €3000 in the first step and didn't win. So you immediately add another €1500. If that doesn't work either, you go to the next instance?

The €11,000 is important insofar as no repair approval was granted due to the amount and the exceeding of the "determined" value.

At the moment, this is not only a loss-making business, but madness. The vehicle was worth about 8,000.

So you are indeed rationally capable of economically assessing your actions.

The 11,000 € are important insofar as, due to the amount and exceeding the "determined" value, no repair approval was given.

Will the legal dispute (the possibly forthcoming forecast) cost you more than 11,000€ minus 3,400€?

If yes, it would be rational to just pay for the repair if it’s about a "family member."

In the end, it is about a residual value for you on a personal emotional level of
a) 4,600€ (8k - 3.4k), which you could economically senselessly save with
b) 7,600€ (11k - 3.4k), so that the "family member" car stays in the family.

You now try to reduce the whole thing via legal disputes to about 3,000€ (11k - 8k). That is a 4,600€ "gain" for your solution b).

Ergo: For 4,600€ you burn life time, damage your health AND spend far more money than the amount at stake as profit.

This is a loss-making business on all sides, not just financially. Or, as you yourself put it, it is madness.

You did something similar once before, at your old job. You considered your successful lawsuit for your old workplace a victory.
In truth, you made your labor and life time available to someone who wanted to get rid of you. I myself would have thought you’re too good for that; you even see it as a victory. For which you also sacrificed a lot of life time again...
Was there no possibility to find work elsewhere with your qualifications?

I am a perfectionist and not a half-perfectionist. That is not always beneficial – rather never, also work-wise.

But then I would have to let myself be overhauled.

That would actually not be a bad idea, to let yourself be overhauled. Exactly "imperfect," both the overhauling and you afterward. Humans are made for inconsistency; total consistency ruins them in the long run. You feel that, you even know that, you say it yourself in other words.

But you still lovingly cultivate your neurotic hobby because you can, of course, always choose the starting point that others are to blame – which may factually be true but misses the core of the matter.

And yes, I stand by "neurotic hobby" as my opinion about it. Based on the above numbers, any other designation is, in my opinion, out of the question.

I would wish for you that after concluding the house story (which surely still gives opportunities for sharp cuts), you come to rest and your physical health improves. And then I wish for you (!) that you find someone to help you overhaul yourself Pareto-style into a Pareto mindset.
Because you only have every minute of your life once, and how you burn it in partly pointless legal disputes hurts to watch.

Being right and getting justice are two different things. The realization would probably help. Is there no one in your family who has an eye for the scenario and who takes you by the hand? Do they all just watch the show?

That doesn’t work. At least not for me. In the case of the car, the situation was clear to me: the insurance company wants to cheat me here. Given the clear liability and facts, I did not expect a lawsuit. When it did come to that, there was no turning back because I don’t want to end up stuck with the previous costs. Ultimately, I see good chances of winning this thing. The judge also hinted at this. I have long since changed professionally and am self-employed. If, as you say, humans are made to be inconsistent, then I am the exception. I am consistent, but not at any cost.