The ballot you received is your valid ballot for the primary. The address on your voter registration at the 30-day-prior-to-election deadline is used to determine your precinct and what you are eligible to vote for. Any changes made after that deadline will not go into the system until after the current election is certified.

So vote your ballot, and call 296-VOTE or go online to change your address:
http://wei.secstate.wa.gov/OSOS/VoterVault/Pages/MyVote.aspx

(Source for above info: the helpful folks at 296-VOTE)

From the voter's pamphlet:

"If your voter registration record does not contain your current name or address, it may affect your voting status. Note the deadline for changes. Changes to your name and address must be made 30 days before the August 18 primary election to legally entitle you to vote using your new name or to vote in the precinct associated with your new address."

So, it doesn't specifically say you can't vote in your old precinct, it just says it "may" change your status. I would call to make sure. Obviously, parts of your ballot are determined by your address, so there may be specific limits to how far you can move, or how long ago you moved, and still be able to cast your ballot without a challenge.

I don't know. Call the King County Elections office and ask them; I'm sure they can help.

206-296-VOTE (8683)
TTY: 206-296-0109
FAX: 206-296-0108

They're open from 8:30 to 4:30.

Yes.