One compromise would be to have the instructions/intro entered into a demo page that people could interact with but not save - it would encourage exploration of the interface without encouraging/requiring people to enter their own info. TaskPaper for Mac does something like this in an appealing way, and has almost the same interface as WorkFlowy.
Yeah, that's a good idea. We messed around with that, but didn't quite get it right. People got too engrossed in that and never really got around to creating their own stuff. The jury is out on it, though. We're definitely not happy with our onboarding process as it currently stands.
