Unable to answer "What’s the surface here?" – on bridge: Foot Path – way/202334235 via StreetComplete 61.3:

Steg aus blauen modularen Plastik Schwimmkörpern

"opening hours: 10-20h (see: https://strandbad-breitungen.de/)"
OSM snapshot date: 2025-08-08T13:08:07Z
POI name: Strandbad Breitungen
POI types: landuse-recreation_ground
#organicmaps android

"opening hours: 10-18h (see: https://strandbad-breitungen.de/)"
OSM snapshot date: 2025-08-08T13:08:07Z
POI has no name
POI types: fee-yes leisure-miniature_golf
#organicmaps android

"is located in nr. 22"
OSM snapshot date: 2025-08-08T13:08:07Z
POI name: FUNK-Shop Melborn
POI types: shop-electronics
#organicmaps android

"Checked locally, does not exist (anymore?)."
The place has gone or never existed. A user of Organic Maps application has reported that the POI was visible on the map (see snapshot date below), but was not found on the ground.
OSM snapshot date: 2026-03-10T00:09:11Z
POI name: Laavu
POI types: amenity-shelter-lean_to
#organicmaps android 2026.03.12-2-FDroid

abandoned toilet hut, can be used as shelter. facing Torne river, doors and toilets themselves are removed
#organicmaps android 2026.03.12-2-FDroid

"predominant rock with a view"
OSM snapshot date: 2026-03-10T00:09:11Z
POI has no name
POI types: tourism-viewpoint
#organicmaps android 2026.03.12-2-FDroid

"copper(?) sculpture of two women holding hands in the wind. no on-site description found"
OSM snapshot date: 2026-03-10T00:09:11Z
POI has no name
POI types: historic-monument
#organicmaps android 2026.03.12-2-FDroid

"statue of a sailor with a boat steering wheel, no further onsite description found"
OSM snapshot date: 2026-03-10T00:09:11Z
POI has no name
POI types: historic-monument
#organicmaps android 2026.03.12-2-FDroid

"wooden model of a boat in a sand pit, approx 5x5m"
OSM snapshot date: 2026-03-10T00:09:11Z
POI has no name
POI types: leisure-playground
#organicmaps android 2026.03.12-2-FDroid