Some buildings are missing here. More are missing near the addresses a bit to the north.
(Is there somebody in particular who handles such imports in Zealand (Sjælland)?)

What is this object?

Der køres med grove køretøjer på Kulsbjerg Øvelsesplads, så der er et stort antal spor, der hverken har grus eller asfalt, og som er for grove til, at almindelige biler kan køre på dem.
(Se bare på terrænskyggekortet.)

surface=dirt
smoothness=very_bad

Jeg tænker, at jeg vil nedgradere disse til disused:highway=track, så man bedre kan identificere de mere egnede veje.

There's a building missing from OSM here, as well as two nearby sheds.

way/469784566
Does this path through the forest still exist? If so, it should be adjusted using SDFI Terrain Shadow Map.
Does this path cross the ditches using bridges or culverts?

A number of Tags have been put on the Line
way/1314066938/history
instead of on an Area.

The associated schoolgrounds multipolygon Relation
relation/18019595/history
covers schools all over Zealand. It might go against the "Relations are not categories" principle.

There is a weird construction here. Presumably, it aids in sea navigation, but what is it and what is it called?

Der er et antal lokaliteter på Bogø, der er navngivet på f.eks. SDFI DTK Map25, men ikke på OSM:

- Gammelby (NØ-enden af byen)
- Nyby (S-enden af byen)
- Skåningegårde (NV)
- Vesterskov (V)
- Vinkælderen (NV) (different from Vinkældergård)
- Husmandsmose (V; vestfor Vestergård)
- Bredemade Eng (SV) (sydfor Enggård and Bredemadegård)
- Galgebanke (S)

Jeg ville placere dem selv, men jeg kan ikke helt regne deres placeringer ud.