Unable to answer "Who is allowed to park here? Parking may be free or paid." – Parking Lot – https://osm.org/relation/10167996 via StreetComplete 58.2:

This lot is permit parking, but only between 7 AM - 5 PM on Mondays thru Fridays.

Attached photo(s):
https://westnordost.de/p/241540.jpg