Typically $150-180k is salary, and then benefits on top of that, so if you're at one of the bigger companies that offer RSU's your total comp is closer to $200k. But $170k is fine, and unless you're in a great tech area already, you'll likely make more connections.

Rent for most software folks is $1600-2500, the UW district is cheaper since it's a notch down from other areas. Ballard or Capitol Hill would be better, that or Ravina or Freemont. All great places for 30-something yuppies.

Depends on where you're coming from to say whether you'll like the weather, but it's not cold in Seattle, it has a lot of overcast and drizzly days though. Folks that like the weather here appreciate the mildness, not too hot and not cold. Outdoor stuff galore, lots of mountain related stuff, craft everything foodie scene, nerd gaming galore.