I agree with BurgessDonnelly on this one, consistency is primary. You can leave county in or out but be consistent. Part of the equation has a little to do with your audience, it also has to do with how you intend to finally use the data. Since many of my clients are in the US, I always add the Norwegian equivalent of State which is "Fylke" and the US equivalent of county which is "Kommune". This way they can understand the Norwegian structure. But when I am researching in the US for someone in Norway I would include the term county or township. I carry this thru for the entire set of places. In my personal database I never use the divisional terms because I generally know them already and then when i eventually update the book or make a family reunion presentation, I write a chapter or talk about the various divisions so my readers and listeners understand the divisions.
In general I do not use the PNA at all because I can't alway trust it, and I also use place for more detail like cemetery names and house addresses. I also use Google Maps to map locations and find X/Y coordinates and then store them in the GEDCOM database, which unfortunately FTM does not support. I also keep an small database of historical place names with hopes that place gets expanded in my primary database.