Her er tydeligvis ikke tale om gågader, så jeg ruller lige tilbage

Please do not touch the imported danish adress nodes

Please note that these points are adresses, not doors or entrances and that our bot will eventually move them back to their positions in the official database from where they were imported.

Lots of stuff in the wiki needs to be cleaned up. Nothing new there.
I agree that having both building=castle and historic=castle can appear confusing. Often it would make sense to have historic=castle on an area encompassing more than one building though. That's where it starts making more sense to use building=castle.

It may not be in iD's menu list. That doesn't make it incorrect though. Not being documented in the wiki doesn't necessarily make it incorrect either. Taginfo counts ~1760 examples in the OSM database: https://taginfo.openstreetmap.org/search?q=building%3Dcastle

It would have been enough to just add historic=castle. building=castle was never incorrect

What makes castle "incorrect"? The building is a castle.

Platforms etc are tagged at most stations (see i.e. osm.org/way/248888190). Wouldn't that be enough for showing "where you can get off and on the train"?

I have removed this because it was a duplicate of osm.org/way/175208408

1 is not a practical reason. 2. developers of road routing algoritms appears to do quite fine without messing with OSM data.
Please do not split anymore.

Why exactly do you think you need 1 segment per station?

Is there any practical reason behind this?

Please note that the changeset title is rather misleading and that I've reverted the changeset

Any good reason for splitting these?

Also please note that I've reverted all of your edits so far.

Please note that I've reverted this change, since there was no obvious reason for it

Both are valid. Personally I much prefer waterway=river

Begræns dig helst til max et land per changeset

I have reverted your change to Jylland.
Also please stíck to max 1 country per changeset, because all editors in the countries covered by this changeset box will see it in their history

I' ve converted all these image tags to osm.wiki/Key:wikimedia_commons

When editing in Denmark please use our national SDFE aerial imagery, which is updated every spring and generally much better aligned than all other options