I just installed everything and then deactivated the apps up to bottom. Looks like maps needs Play Services (GPS) installed and running. But you can block any permission, as far as I can say. Play Store is necessary, as well, but you can complety deactivate it? Looks like its only checking if you have it installed, at the moment. Running Play Service seems to be mandatory, though.
Not sure about GMS and GSF. Will do further tests to minimize the area of attack.
Edit: Service Framework (GSF) can be deactivated, as well. Maps appears to run on Google Play Services and Play Store, now, with Play Store deactivated and Play Services set to bare minimum in app settings.