1) No, you can't automatically email non-users auto-reports.
2) You can't select non-users as receipients of an auto-report (I just tested it) - only users.
3) I think it would be useful - I've passed it on to the product managers as a suggestion. Though why would they not be a user? It's probably either a) it's costly for you to add them as a user, or b) they're not computer-savvy enough to go to a website and see the auto-report on their home page. I can't help you with a), but for b) keep in mind that you can set it up to open to the Today page every time and the reports are right there...very easy.
In the meantime you can run a report and then use the Send wizard to send it to a non-user. Give it a shot! Also gives you a chance to review the report before you send to your boss