I recommed Pixel phones with GrapheneOS or any Lineage OS supporting device. Linux phones are good but I dont personally think they are reliable as smartphone.

I might be expressed myself wrong. Because of my poor English😅 I mean, the last step to change is the iPhone. To the Android alternatives with custom OS. Especially Google Pixel phones with GrapheneOS.

DeepL with PWA or browser shortcut is the way for me. LibreTranslate keeps bugging.

I recommed Tuta for mails. May be not good as Proton but not American, not from Google and most important, private as Proton.

Very good. Next step should be the iPhone