I love Seattle, but I should warn you that I’m both introverted and very comfortable with rain. (The rain thing is not a joke. Except for a couple months in the summer, it really does rain a lot.) If you want to go somewhere with sunshine and extroverts, Seattle would not be the place.
Seattleites are (stereotypically, with many exceptions, of course) extremely polite but not necessarily friendly—lots of “have a wonderful day!”, but not as much “we should hang out!” Definitely a nerd culture there, though, considering all the tech companies, and there is indeed a thriving kink scene.
My favorite thing about Seattle is all the nature; there’s mountains and forests all around you and a very short drive to a variety of gorgeous wilderness. If that’s something that feeds your soul, you might like Seattle; if you’re looking for somewhere that people are super open and welcoming, you might not like it.