Can you hint me to one of those German laws which do require one of the above?
It literally translates to "federal data protection law" and has been German law since 1978. In certain conditions it has also mandated a DPO (https://de.wikipedia.org/wiki/Datenschutzbeauftragter) since then, but in fact the first DPO position in Germany was created in 1971.
The right to be forgotten is mandated by article 35 BDSG (https://www.gesetze-im-internet.de/bdsg_1990/__35.html).
The right to a data export is mandated by article 34 BDSG (https://www.gesetze-im-internet.de/bdsg_1990/__34.html). It has always been common use this law to get a free copy of the data which our credit reporting agencies have about you, I've done that multiple times.
However, if you do that, good luck ever getting a mortgage, credit card or other post-paid services ever again if all credit report requests come back with the reponse "no data available". So I wouldn't recommend that.
How does that work for people who never had a Schufa history? If for instance I decided to move today from Brazil to Germany, would I be unable to do all these things there, since they would have "no data available" on me?
It's especially funny when small to medium German companies suddenly panic because of the GDPR and when you look at their situation all you can say is "yeah, you should have implemented that 15 years ago, it's already been German law that long".
In Germany not much will change, but at least companies like Facebook can no longer just move to another country with worse privacy laws (like Ireland) and call it a day. For us the GDPR means that protecting user data will no longer be a competitve disadvantage. But if you're a small company and handling data reasonably, the GDPR won't hurt you anyway.