Welcome to OSM! Please use the changeset comment field to describe what you changed and why. For example, "Added a post box and adjusted a building's height." There are more examples here: osm.wiki/Good_changeset_comments

Please use the changeset comment field to describe what each change does and why. For example, "Remove a building part because it no longer exists." See this page for more examples: osm.wiki/Good_changeset_comments

Alright. amenity=place_of_worship is for entire churches, synagogues, temples, etc., and from your description and the time I visited, it seemed like these were all just divisions of the Home Church. If they all have their own services, congregations, etc., then I'll change it back.

amenity=place_of_worship is an inappropriate tag for individual classrooms for one church. That implies that they are all each their own church.

If there is no other way to tell for sure, then I guess it's okay, but I'd rather be inclined to leave it untagged. If we don't know some information then it's better to say we don't know than to take a guess.

I don't trust that map for the accuracy of speed limits. I've been on a few roads where it the online map is very different from the sign (like 25mph online vs 40mph irl)

Santa Clara LAFCO is authoritative for the boundaries of cities within Santa Clara County. It is not the authority on addresses within the cities, or roads, or anything else.

The import was from an authoritative data source, the City of San José. You can browse the data here: https://csj.maps.arcgis.com/apps/webappviewer/index.html?id=3c5516412b594e79bd25c49f10fc672f

Anything that physically exists is valid to map, even if it's illegal or dangerous to traverse. In these cases they should be tagged with the "access" or "hazard" keys as appropriate. Otherwise someone will just add them back later.

You can see the history of an object by following its link and clicking "view history." In this case way/810015282/history we can see that it was from an import changeset/85987477 I also notice that the building had an address on it, which seems like valuable information to keep somewhere.

Please use descriptive changeset descriptions: osm.wiki/Good_changeset_comments The "name" field should be for the name of an object, not the route number: osm.wiki/Names I've reverted this change in changeset/138682086

If an object was previously known by another name, it's helpful to put that in "old_name=*" so that people searching for the old name can still find it.

When improving the geometry of a feature, it's better to add and realign the existing feature than to delete and re-draw. See osm.wiki/Keep_the_history . You can add nodes to an existing way by dragging the arrow between two nodes.

access=no doesn't mean nobody at all can ever use it—otherwise, it wouldn't exist. It means it can't be generally used, but that can still allow for e.g. emergencies or maintenance workers.

If the stairs are accessible from the freeway, they need to connect to the freeway in OSM too, even if it means an awkward crossing to the centerline. This ensures a proper routing network.

When objects close down, it's often better to re-tag them with a lifecycle prefix osm.wiki/Lifecycle_prefix than to delete them entirely. This way, any potential future features can re-use the old data, for example geometry or address/phone tags.

Anything that physically exists is allowed to be mapped, even if you're not allowed to use it. In these cases, consider access=no. I know it seems silly to try and maintain a routing network of inaccessible paths, but I could imagine for example an app that would find the nearest freeway refuge in emergencies.

Nice!

You can map traffic signs, including speed limits: traffic_sign=* and I don't think it's redundant to do so: the sign is a physical object that can be mapped, and the limit is an attribute of the road or rail.

Do I understand right, that the fixme asked how to tag something, and because there is no tag for it currently, you simply removed the fixme? If a tag for it is made in the future, that will make this hard to find.