Should I go to Seattle this summer?

I wouldn't if you want to remain safe.

No, you shouldn't. This summer is not a good time to travel anywere.

I'm actually going to Seattle next week.  I'll let you know how it went!

I am aware of the autonomous zone in Capital Hill and will avoid that area.  That is the primary area of protests in Seattle. As for your plans, it sounds like you'll only be in Seattle a limited time.  Just wear your mask, keep a jug of hand sanitizer with you and you should be fine.  From what I heard, most things are still pretty slow downtown and most tourist spots as of now are still closed.  But they could open by August.  I'm mainly going for photography and relaxation though I will be visiting Pike Place for lunch as I do that on every trip.  I've already have done all the touristy stuff.  

Given the pandemic, you should be avoidant of crowds and Pike's Place is one of the most crowded ones. Give your health top priority, and perhaps even stay home. Seattle is a very crowded city.

You should not go to any touristy places, in any state.  Either they will be closed or they will be crowded and the risk of getting the virus will be too great.

Washington has done a good job of bringing down the number of COVID cases. You need to google and see what stage of opening up they're in, and when they expect to move to the next phase.That's the only way to know if places like Pike Place will be open. 

I suggest you keep a close watch on which phase of opening up is happening in the counties/parks you wish to visit.

https://www.governor.wa.gov/news-media/chart-washi...

https://www.dnr.wa.gov/open

Protests?  They have a militant group who has physically seized control of the city's capitol hill including occupation of the police station there.  This is no 'protest'.  You need to make a moral choice as to whether you want to support an economy and government where the mayor supports such tyranny.