Yes, but Seattle being Seattle it is not populated by the kind of people who will pack heat. That's like saying "well Austin is part of Texas so why doesn't everyone wear a cowboy hat and go hog hunting on the weekend." Both those cities are basically San Fransisco demographically speaking.
And just because concealed carry legal doesn't mean the process is constructed in such a way that normal people can actually do it (see CA, MA, NYC and NJ for examples of this) though I'm not sure about Seattle specifically.
It is currently, but Nick Haneaur and the I-1639 crowd are doing everything they can to not so gradually chip away at gun rights for law abiding WA residents.
Probably. IIRC most states are. Pretty much nobody who isn't a security guard or armored car employee who's actively working open carries not on their own property in any state.
And just because concealed carry legal doesn't mean the process is constructed in such a way that normal people can actually do it (see CA, MA, NYC and NJ for examples of this) though I'm not sure about Seattle specifically.