The extent of this tag <natural=water; water=stream> seems inappropriate, as the "median of the maximum water levels of all months of the year" should be mapped. This is here certainly not the case.

It also gives the wrong impression of a lake in this area, where it is actually just a riverbed.

It would be better to map just the main stream or the two or three most important streams here. The whole are should be tagged as waterway=riverbed

See also
waterway=riverbank
and
osm.wiki/Proposed_features/waterway%3Driverbed

walk bridge

manque passage avec escaliers

via StreetComplete 12.2

Attached photo(s):
https://westnordost.de/p/4390.jpg
https://westnordost.de/p/4391.jpg

How to set up the right rendering orientation (the small triangles) on cliffs ?

This Road may have restricted access.
Diese Strasse ist möglicherweise nur Zubringerdienst.

Gerichtsurteil aus 2009, welches diesen Umstand sowie die Totalsperrung ab Euschelspass nach Schwarzsee erwähnt:
https://www.fr.ch/tc/files/pdf2/603_2008_223_210_221_224_02_07_09.pdf

The place has gone or never existed. This is an auto-generated note from MAPS.ME application: a user reports a POI that is visible on a map (which can be outdated), but cannot be found on the ground.
POI has no name
POI types: building
OSM data version: 2018-05-26T22:39:02Z
#mapsme

Espace Bio La Sage, Boulevard de Pérolles, Fribourg

escaliers

escaliers

escaliers.