How Plausible Is Self-Hosting Everything and Still Have a Normal "digital Life"

Some good advice there. I especially agree with learning to do this stuff band seeing how you enjoy the lifestyle, before you commit to no cloud services. You might find your definition of normal changing as you get into the hobby.

I very much like the advice about using a file encryption tool like Cryptomator and then uploading the files to a mainstream cloud provider. For instance, on Joplin my notes are encrypted and uploaded to dropbox, it works like a charm even on smartphone.