Could you please do this in smaller chunks? It makes it easier to review and fix mistakes (and there are quite a few here, such as every bridge I've checked so far).

You appear to have used the highway traffic signals preset for a railway signal at node/7290148178

Did you use the wrong signal preset here?

I've removed the highway designation and reverted the roads back to "highway=secondary".

I've removed the highway designation.

I've removed the highway designation.

The user is editing using maps.me. As far as I know, the app gives no control over when or how much it uploads, so world-spanning bounding boxes are normal for it.

Is "edifice_height" the same thing as topographic prominence (https://en.wikipedia.org/wiki/Topographic_prominence)? If so, there have been intermittent efforts to establish the tag "prominence" for that, and I recommend using it rather than something completely undocumented.

Looks good to me. The building was mapped back in 2008, and even the oldest imagery shows a parking lot. I'd say it was demolished a long time ago.

You've changed part of the Missoula border (way/34746177) into an improbable-looking shape. Was this intentional?

Please don't add nonsense to the map, even if you find the local traffic engineers' obsession with roundabouts annoying.

Is this an import from somewhere? Most if not all of the volcanoes you've added here duplicate existing ones.

You can mark a trail as "unofficial" by adding the "informal=yes" tag to it. It's not one of the tags that the iD editor provides by default, so you'll need to add it manually:

1. Select the trail in the editor
2. In the panel on the left, scroll down to the "all tags" header and click on it.
3. Click the plus sign
4. Add "informal" to the left-hand box and "yes" to the right-hand one.

(The "informal" tag is also useful for other things like unofficial parking areas.)

Where are you importing these buildings from?

You've added a service road with the type "Kallispell Access Lane". Was this supposed to be a name?

The usual way to tag this sort of business is as a "Cafe" with a cuisine of "coffee shop".

Welcome to OSM, and thanks for adding businesses to the map!

Something to keep in mind when you're editing: when you add a tag to something, the editing software sometimes automatically applies additional related tags. For example, when you added the "Storage rental" tag to Skyview Storage, the "building" tag also got added, making it look like the entire area is a single building. You can remove these extra tags by clicking on the "trash can" icon next to them.

Thanks for your additions.

Elevations in OpenStreetMap are specified in meters. By giving High Camp an elevation of "6123", you're making it one of the highest points in North America. I've fixed it, but it's one of those "gotchas" need to keep in mind when adding things.

"isolated_dwelling" is almost never the correct tag for places in the United States. If you think you've found one while cleaning up GNIS, it's probably either a former town, a former railway stop, or you need to look around to find the rest of the hamlet.

Please don't glue unrelated objects to roads like you did with Town Square Park here. It makes it difficult to modify the roads later, such as when splitting one to add lane information or speed-limit changes.