Amprecon: Welcome to WA. It's a great place to live. Your TN permit is ok, but you really don't need a permit most of the time. Unlicensed OC is ok, and fairly well accepted...yea, even in Seattle, but especially over here on the dry side. When it comes time, WA CPL is shall issue, $52.25 for 5 years, no training or extra other stuff required. Put in your app, they take your fingerprints, mail you the CPL in a couple days. You do not need to notify anyone you are carrying, but remeber, when they run your drivers license, they will see your CPL too. Personally, I have never been asked about my carry when stopped, even though I normally OC...I don't get stopped often, but I have been stopped a couple times in the last 40 or so years.
The law is the same everywhere in the state, little local gotya's are not a problem. Law is RCW 9.41. Local gov's can regulate discharge and that is about it. Read Read the Law...especially 9.41.300, it is very simple.
If you are going to Everett you will probably want to live north, or northeast of the city. The closer to Seattle, the higher the price of houses, but even there the price has come down a bit in the last little while...not as much as some places, but a bit. Looking for land, or just a house in the city? Look for land North and east, just a house? You should be able to find that closer to Everett. Roads and traffic? From Marysville (next town north of Everett) south the traffic is pretty bad (IMO), north of Marysville, not so much.