Thank you for your answers. My native language is German. Sorry for my bad English and your understanding. I'll make short sentences now. I use Netguard firewall from GitHub. i would continue to use it in Graphenos.
Sometimes Netguard went down for a short time. You don't always notice it straight away. That's why I'm asking whether additional blocking is possible without root.
I have heard that a VPN firewall does not always block all network traffic. There are supposed to be small gaps. At least this has been recorded by users. But that was a few years ago.
The other question related to the Google photo storage. I'm currently testing PixelOS on a Samsung Galaxy Note 10 Plus. The free unlimited photo storage is active there, as with the original stock.
But that would just be a bonus. I'm determined to buy a Pixel smartphone and run GraphenOS on it. I hope that the apps that require Google services will run on it. The most important apps would be WhatsApp and the DKB banking app. Unfortunately, I need WhatsApp for other parents who only use WhatsApp.
I also like reading Mike kuketz. Many thanks for your help and answers.