Ok so I disabled:
- Camera and replaced it with
- Open Camera (works, but I can’t start it with the camera button although FP said the button would be "programmable)
- Maps
- OSMand (didn’t test yet)
- Calendar
- Etar + Offline Calendar (works)
- Chrome
- Firefox (works)
- Contacts
- Drive
- Gmail
- k9 Mail (works)
- Google App
- Google Contacts Synch
- Google Play Movies & TV
- Google Play Music
- Google Play Services
- Google Play Store
- F-Droid (works, duh!)
- Google Text-to-speech Engine
- Hangouts
- Youtube
- NewPipe (works)
Google Services still running in the background during all this testing (according to Settings > Apps > Running)
- None