What are the dangers I face? I have replaced Gmail with ProtonMail, and WhatsApp with Signal. What are the risks of keeping the old apps on my devices? Should I delete all Google Apps? If I optimise everything for my privacy, but use one bad app, does all of my work get undone? What apps should I absolutely not have? 

In the end, I am just asking this: is it really possible to become 100% (or close to that) safe while still maintaining contacts and being productive? 

I don’t know much about privacy; I would greatly appreciate links to beginner-level content.