If you're going to be traveling up and down what we call the I-5 Corridor (Vancouver, BC to Portland) but mainly centered in North Seattle, I'd look to live in maybe Lynnwood or so... further to the east or a bit further north if you want out of the major urban area. As near any big city today, it's a matter of traffic. The closer in you live, the shorter, but more crowded, the commute.
As to the rain, not as bad as painted. Lots of rainy days, but on many of them, it light enough that you do stuff anyway. I've shot an entire 3D course twice around on a "rainy" day and come back damp, but not soaked. We refer to such days like the Irish: "the air is heavy today, isn't it?" Course, if it's gully-washin', our rain's as wet as anybody's.