Private home, which insurances do we need?

Would it make sense to take building including natural hazards and household contents insurance from one insurer? Or does it not matter?

Usually there is about a 5% discount. But just because one company is top in one insurance, it is rarely the same with others.

Can it happen with damages that two different insurers try to avoid paying and say the other insurer has to pay?

Yes, that happens quite frequently....

I have seen about 60-65€ (building + natural hazards + household contents) per month, that seems quite a lot to me.

For the building insurance including natural hazard coverage, I have a group insurance with Karlsruher Medienversicherung. It runs through my membership in the Bund der Versicherten and costs 200 euros plus the 80 euros membership fee. Household contents including natural hazard coverage costs around 80 euros. This can, of course, vary for you depending on the postal code and type of construction or building costs.

Are those 200€ and 80€ per year? Then that is extremely cheap If they would gladly shift that to the other insurance, it would make sense to take building and household insurance from one provider

With 80 EUR household contents insurance, I would take a look at the scope of services, that seems veeeerrrrry cheap to me. I have over 300 EUR.

I also have the Ammerländer for household contents including heavy rain and glass in the Excellent tariff for just under €90/year. The Domcura with top protection as building insurance including elemental coverage for about €180/year. Of course, it costs more with elemental coverage if you live in a particularly high-risk area. , your €300 is really something...

(4 Minuten Bearbeitung waren um) Additionally, a locksmith service was offered to me through chk24 for my household insurance for just under €18/year via Roland Versicherung.

With 80 EUR household contents insurance, I would definitely take a look at the scope of services; that seems veeeeeerrrrrrry cheap to me.
I pay over 300 EUR.

That is very expensive. But maybe you also have things included that others don't have (and don't need). We also pay around 80 euros.