I agree with your point 1, Terry. Depending on the circumstance (e.g. how comfortable I am with the client or content), I'll make a flowchart, with each node of the flowchart representing a screen.On each node I'll just have a title (will probably become the screen title), and a sentence or two describing, in the broadest sense, what would be covered on that screen - not how it will be represented or how it will look, but the concept(s) to be addressed. I'll usually do this flowchart in Powerpoint or Visio and, for example, a 30-minute module might have around 20 nodes describing the flow.
This high-level flowchart can usually be put together very quickly (in a few hours) and is a useful tool/step that:
1. Helps get agreement that all of the material that has to be covered is represented.
2. Helps crystalise how the navigation and chunking will hang together/flow.
3. Gives me confidence that the next stage (maybe prototype, maybe storyboard, maybe direct build) won't be too far off-piste.