Okay here are some pure headcanons that I love:

1. The Heeres and the Hansens being related and Paul and Heidi having a sweet romance and Evan and Jeremy having a cute, happy family, as pictured below:

2. Modern Newsies AUs where Medda is Jack's foster mother.

I have more pure headcanons, however, I can't think of them now, so there may be a part 2.