A few friends and I wanted to come in dressed as Disney Characters and Superheros and maybe pass out treats, flowers, books, words of encouragement, etc.. Would that be possible?

I think u would need to call them to make sure it was ok

Contact the Dornebecker founders. They do have the Portland superhero coalition that goes there once a month for the kids. I believe due to copyright infringement they cannot have names of the actual characters and less you have permission through Disney Marvel Etc but here's the link https://www.ohsu.edu/xd/about/dchf/fundraising/fod/

Contact HR for the hospital.