should this railway be tagged with service=spur and not service=yard? I'm not familiar with how to categorize railways yet...

The desert line is apparently disused, and blocked by rockfall.
If you know which sections are still in operation and which are disused, here is the correct way for tagging: osm.wiki/OpenRailwayMap/Tagging#Tracks

Unable to answer "What barriers are used at this railroad crossing?" – Railway-Road Crossing – node/11571977544 via StreetComplete 62.2:

it is lane inside railway factory

Unable to answer "What barriers are used at this railroad crossing?" – Railway-Road Crossing – node/8547059965 via StreetComplete 62.2:

No crossing here. Solid fence, no gate on one side

Old railroad bridge, see https://de.wikipedia.org/wiki/Datei:Bahnbr%C3%BCcke.JPEG

Unable to answer "What barriers are used at this railroad crossing?" – Railway-Path Crossing – node/7884493264 via StreetComplete 62.1:

No railway line here.

school

what is this thing lol

Here is a new rail loop visible on Esri Wold Imagery. I'll let someone familiar with canadian rail stuff add this.

Proper boundaries of Muckleshoot Reservation are not shown.

Please refer to the ArcGIS map made by the Muckleshoot government to fix this and any future issues: https://muckleshoot.maps.arcgis.com/apps/webappviewer/index.html?id=94cdfbd5be64494eaf866a7277aa1a57