How can I get my Angular 2 app to work with barrel file imports?

you have to make few changes to make barrel work,

index.ts

   export * from './heroes.component';

systemjs.config.js

Add an entry to map like below,

  'heroes':                     'app/heroes', 

then in packages make an entry like below,

  'heroes': { main: 'index.ts',  defaultExtension: 'ts' },

This will resolve barrel issue, but does not completely resolve all your issue as you have reference to hero-detail as well inside heroes component, so you have to work on those.