I contacted the county highway district and they said the corrected sign should go up in the next couple of weeks.

There's no way with the ID 900000000, but you created the next ID right after, 900000342. Congratulations on (sort of) creating the 900 millionth way!

I accidentally put the changeset comment in the source field. Oops.

Sorry, subdivisions. There's a lot more than one...

I'm not sure why the tag was different on these nodes, but thank you for fixing it.

These are residential roads.

Surveys, checking against existing data, and verification through the county assessor.

I'm not sure where you found East Calabrese Lane, but the street is actually named East Bellalucca Lane.

Well, should've checked what exactly was changed. It removed access=private from the roads that will be private once constructed. Oops.

Turns out Paschal Lane was the correct spelling. Oops.

I'm not sure where you got "Lauch Street" from. There was a road here with that name about a decade ago but it was demolished when the distribution center was built.

Also, is the baseball field at Rocky Mountain High really called "Baseball Field"?

It is preferred to map turning circles (fake cul-de-sacs) as nodes on the street rather than drawing a line following it. Unless the road physically splits, and even then you can still use a turning loop, just the turning circle is fine.

Is this really a religious office, as opposed to a church? Last I remember, this is the site of a church.

Owyhee High School isn't slated to be complete until this summer. It also seems like the school will be built south of the subdivision under construction. I changed this, but let me know if I am mistaken. Also, the linked page seems to be broken, and as far as I can tell Owyhee High School doesn't have a site yet.

It seems likely that these houses have square corners. If this is true, make sure to square them by selecting Q after drawing them. Thank you!

Welcome to OpenStreetMap! For some chains, such as Chevron gas stations, there is a preset in the iD editor for them that automatically populates many of the tags. I fixed this for the gas station since I assume from your changeset comment that it's a Chevron brand gas station. Thanks for adding these features!

I doubt this park is really called "Park (Private)". If it doesn't have a name and it's not publicly accessible, add noname=yes and access=private.

Looking at Taginfo, it seems like highway=construction is more commonly used than the lifecycle prefix. What are your thoughts on one over the other?

A lot of these areas are still under construction. To reflect this, I updated some of the tags to landuse=construction.