You’re welcome! I think this is something that doesn’t really impact someone (especially if you use the simplelogin add-on), but adds a lot of privacy.
Oh boy there is a lot.
Browsers: Firefox sadly is not something I would recommend due to missing security (you can read a bit about it here Firefox and Chromium | Madaidan's Insecurities). While Firefox can be used privately and securely, it is much harder than with other browser. I would go so far and say that even some closed source browsers like https://www.epicbrowser.com/ are a better option for your privacy.
You also could add TOR with a usability warning. TOR is not usable for everyone, but can be a decent option.
2. Switch Up Your Search Engine
SearXNG · GitHub based on searx, but with better functionality. Take a look at searxng, might be interesting for you.
3. Use a Password Manager
Cloud based password managers can still be really bad, only use them if you are unable to have any kind of backup.
4. Get a Better Messenger
Really good recommendations.
5. Minimize and Scrutinize Apps and Browser Extensions
Add FOSS alternatives as you mention them below. For example Free office suite for Windows, Linux and macOS | ONLYOFFICE as a replacement for Microsoft Office.
6. Sign Up for a Privacy-Respecting Email Service
Protonmail is a good choice. Also mention the other benefits paid Protonmail has (simplelogin, protondrive, protonVPN).
7. Eschew IoT Devices
Just yes
8. Limit Social Media Usage
Just yes, but add some more private alternatives like Mastodon. Also add replacement applications for e.g. YouTube and in general ways to still access social media, but from an alternative frontend (invidious, nitter and so on)
9. Change Your DNS Provider and/or Use a VPN
Mention that ProtonVPN is included in the monthly $12 proton tier.
10. Remove Your Data from People-Search Sites
Just yes
I would add something like “If you want to discuss this topic more, you can join privacy and security focused forums like http://discuss.techlore.tech”