How does Linux compare with either MacOS, Windows, or just using an iPhone? Any particular distros that are more secure than others, or software to include / not to include?

I assume Android is a bad idea because of the ease of picking up spyware and the privileges that such software can have once downloaded?

What's the best way to secure your web browsing & search history? Being an ex-Googler, I can think of a couple things to do - don't sign in to Chrome, turn off your Web & App activity, turn off location history and don't grant permissions to use the location service - but I'm curious what the non-Google threats would look like (honestly, I don't believe Google is your biggest threat for a freedom activist).

What would you recommend for sharing documents, source code, or other permanent work/organizing products?