Engineer here as well.
I moved to SW Washington about 5 years ago, and started surfing that summer. I've probably spent about 20 nights outside within a quarter mile of the beach. i have never had an issue with bugs. keep in mind in OR that the closer you get to the coast the wetter it is going to be. Summers are typically dry for the most part with a few days of rain here and there. while I have never had an issue with misquitos and the like, I've always camped in a tent. There is almost always a breeze on the beach, but it's not always out of the west. a lot of times the wind will be out of the NW and some of the coves well block you from the wind for the most part.
Yes, you will get some warm days. Usually summer days start in the high fifties and end up in the low 70s for the high. I'd say about 10 days out of the summer you'll get temps up in the mid 80s. It's hilarious, northwesterners will make you think you're in SoCal when it gets warm. It will be 80 degress and people will be attempting to swim in 49 degree ocean water.
Enjoy your stay. I'm still taken away when I drive the pacific coast highway in the summer time. There's nothing quite like it. And here's a link I use for surf forecasts, but you might find it handy for your travels as well.
http://magicseaweed.com/[This message has been edited by itgoes211 (edited 12/21/2009 5:29p).]