RuedigerJoe What actually happens, if i do not sandbox this app?
RuedigerJoe I know i can sandbox this app, but that would be inconvenient, since i had to switch profiles
Sandboxing and profiles are two different things. All apps on Android are sandboxed. There's no option for that. I'd read up on user profiles. Personally, I wouldn't go through the trouble of creating a new user profile just for an app that has trackers.
Profiles are more for separating apps for different uses, like work, personal, social media, and games. That's just an example, of course. You can utilize profiles however you'd like.
RuedigerJoe Does it communicate with other apps?
unlikely, but technically possible
RuedigerJoe But can it gather anykind of infos about me or my device, location whatsoever?
I'd read these two sections: about hardware identifiers and the one below it about non-hardware identifiers.
As for location, you'd have to give the app access to location for the app to share that info.