1) We need a three-story limit all across Portland? Even downtown and Lloyd Center?

2) 5-story buildings do not create "dark canyons". Vast sections of European cities are 6-stories max, and they are fine places to live. 

If Portland can't even get support for 6 story buildings on major commercial streets, it's just going to get more and more expensive. It may never get as bad as San Francisco, but it'll be bad.