In this case I can testify that in my personal experience these problems have been fixed with FPOS, especially through upgrading to Android 6.0, as I explain in this post FP2 random reboots - see #rebootsguide for help
The random reboots progressively disappeared, and the battery life improved significantly, even though I used facebook.
There’s a facebook alternative (actually there are several) that is open-source and reduces the tracking by FB. It also covers FB messaging.
Moreover, you can also find the open-source public transport app Transportr on F-Droid, though you’ll have to find out by yourself whether your city is supported by this app.
Hope, this helps.
No, raccoon and Yalp Store are mere Play Store alternatives. They just let you download and install apps from Play Store, but that doesn’t mean apps fully work.
I will try to make this as simple as possible: The majority of apps rely on Google Services to function properly (that is the Google’s trick, here you have an official manifest as well). Google Mobile Services, GMS or, more common, GApps are closed-source (and steal a lot of personal data from you). But microG exists to solve this situation.
microG is a libre implementation of GMS that will make work apps that won’t without them. This, combined with Yalp Store are likely to serve you. Banking apps are more prone to not work due to SafetyNet. You will need tingle to patch the system with every update.
Thanks @tphysm and @Roboe, I am still awaiting a response about my phone being replaced, so currently using a nokia 3310 lol. But I’ll keep you updated once I get the fairphone back and switch to FPOOS. 
I also have the Yalp store, i have tried several apps but most of them don’t work.
I have installed those apps on a separate account of my android, so i can easily agree that those apps read my non-existant contacts 
Any advice for good cycling route planners for European cities that are not dependent on goorgle?
Thank you in advance
Check out OsmAnd (read first post for details).
Do you know what kind of data Google gets, when one uses microG?
When you signin with Google in an app having Google device registration enabled on microG (disabled by default), Google gets your IP, the account you entered and the app you signed in to. The rest is randomized.
When you enable Google Cloud Messaging (disabled by default), then Google gets, with every push message, your IP, the service associated (app) and, depending on how push messaging is implemented in the app, then some other data than could serve to stablish relations.
AFAIK, no more information is shared with Gobble. If any, then it won’t be enabled by default surely. Every other service in microG is implemented with OS services (maps with OpenStreetMap, network location with the backend you choose).
I know some cyclists use Open Cycle Map (based on osm).
Try bikecitizens. It’s on the Play Store, but it works well without any Google stuff here on my FP1.
Aw man that looks exactly like what I need! Thanks mate! 
I installed Yalp recently and it seems to use its own fake account: it didn’t ask me for any credentials. Have they changed their approach or did I misunderstand?
Any arguments pro/against either Yalp or Raccoon (which I used up to now)? In other words, does anything speak against using Yalp rather than Raccoon (not depending on a computer does indeed make it a lot simpler…
I also find Yalp a lot more comfortable than Racoon. I think that Yalp is okay to be used. You should be careful, however, if you use Yalp with your own Google account.
Read more in their FAQ: https://github.com/yeriomin/YalpStore#faq
Said so, I’ve using a specific, disposable account created only for that purpose for the now obsolete NoGapps (microG) BlankStore, for three (or four?!) years now and I didn’t have any problem.
Anyhow, I recommend using the default Yalp Store credentials now that it has them.
Pretty nice list of alternative apps. I leave here some that I normally use a lot too: