Not in total disagreement with a lot of this - and the more I try to think about classifying population centers, the more it feels like turtles all the way down - but here are some of my thoughts:

- For incorporated areas, where exactly the administrative boundary lies can skew the "official" population pretty heavily. For example, Fernley has a much larger population than Fallon on paper, but Fernley's incorporated boundary is pretty huge compared to Fallon's, which is quite small. There's a lot of population that would consider themselves to be part of Fallon that isn't being counted. I'd be willing to bet at a glance that Fallon's official population would increase 50-100% if it had as generous an incoporated boundary as Fernley.

- For unincorporated CDPs, I think it's important to keep in mind that the primary purpose of defining a CDP is for statistical clustering for analyical purposes - while CDPs generally map to something recognizable on the ground, they don't necessarily correspond to distinct settlements, or occasionally even anything folks that live in the area would recognize as a "place". For example, many of the CDPs around east shore Tahoe and in the rural areas of Minden-Gardnerville are just subdivided rural neighborhoods that got clustered as a CDP for whatever reason. Lakeridge, Skyland, East Valley, Ruhenstroth, etc aren't distinct settlements in the same way that Genoa or Wadsworth is. I've spent years working in Minden and never once heard someone say they live in "Ruhenstroth". There's no signage or anything corresponding to that naming either. I'd have to guess that's what the subdivision is named on the assessor maps, but it isn't something that anyone refers to in practice, which is why I'm not huge on using Census Bureau data as a 1-1 map of where "places" exist in the US. That isn't the function of defining CDPs.

- Population is only one factor in the "importance" of a place. I think it's important to consider the level of services a settlement has to offer - ie, someone that lives in a 'hamlet' may or may not have gas and will have to drive to the nearest 'village' to find a small hardware store, someone in a 'village' will have to go to the nearest 'town' to find emergency care, and someone from a 'town' will probably have to go to a 'city' to attend higher education. The reason I downgraded Wadsworth (will most likely bump that one back up due to tribal services there) is that there are nearly no facilities in the town. This is also why I downgraded the settlements around N Lake - someone living in Cedar Flat where there are zero facilities will need to drive to Tahoe City or Kings Beach to get gas or groceries. A bedroom community of 1,000 with only a gas station and a convienience store shouldn't be, in my opinion, classified the same as a small town of 500 with a bank, library, a motel or two, etc. 

- I strongly disagree that a 'suburb' (as we use the term in OSM) needs to be inside of an incorporated boundary. Incorporation boundaries often say more about state and local politics than they do where a city starts and stops, in the common "sense" of the term. If you're using NY's boroughs as a "perfect example" of correct use of 'suburb', this is incorrect - these are official administrative units in NYC with distinct boundaries, which we have 'place=borough' specifically to describe. Where 'town', 'village', 'hamlet' are used to classify places in a rural context, these imply to me at least *something* that functions or looks like an "incorporated" place or a "distinct settlement", whether they are legally or not, as opposed to urbanized place tags 'suburb', 'quarter', 'neighbourhood' which are fuzzier. Geographically, Sun Valley is a distinct place, but it lacks any kind of "center" in the urban or legal context, aside from being the only (NA usage) suburb of Reno/Sparks with its own address. I think it is the closest edge case because of those reasons for sure. But it's hard to see how Sun Valley and, say, Truckee ought to share the same 'place' classification when one has almost full services and the other has only a strip mall or two. Spanish Springs is not a distinct settlement - again, a CDP does not necessarily define a distinct settlement. It is a suburb of Sparks, even in the OSM sense of the word, with no distinct center or boundary. All these CDPs north of Reno/Sparks blur into the urban fabric of Reno/Sparks, the lines only existing in the Census Bureau because of Reno and Sparks' odd patchwork incorporation boundary.